After many months of searching, I ended up with this specific monitor. I have had it for one day and I am amazed by the vibrant colors. I use it for watching movies and it is fantastic. Of course, the contrast is not perfect, but let's not forget that no device can replace the cinema. It has a very good viewing angle and even though I sit about one meter away, it doesn't strain my eyes at all. I haven't tried it for gaming and I don't plan to because I'm not interested. The only thing that gave me trouble was the short cable, but I solved it. Overall, it is a monitor that is worth its money and is a gem on my desk. I will come back after 11 days with 10 hours of daily usage. The screen is fantastic. For anyone who wants to watch movies with quality, I believe you won't find a better one. Also, browsing the internet is a pleasure. I have replaced my laptop with this screen completely. Its stand is perfect and you won't need another one. I regret not getting it earlier. TODAY 5/9/23, I have been using the screen for 6 months. I think I couldn't have made a better choice for movies and internet browsing, as well as social media. The colors are extremely vibrant, it doesn't strain your eyes at all, the viewing angles are perfect even in a completely dark room. I give the contrast an 8 out of 10, but don't forget that there is no screen that can replace the cinema. CONCLUSION. For what I wanted it for, it is SPECIAL!!! I'm not interested in games, so I can't give an opinion on that. I don't use my laptop at all, I only have it connected to the screen. I do everything from there.

The screen is amazing, it has an incredible image and it is a jewel on the desk. It is an ideal solution for office work and for Work from Home in the current conditions.

- Colors are absolutely accurate and pre-set by Dell. Inside the box, there is a paper with the calibration and the results. I didn't need to adjust anything.
- Tremendous viewing angle. You can see everything crystal clear from edge to edge. I sit next to a window with the sun on the left. No problem with glare.
- However, the most important thing is the connectivity of the screen itself. And I explain: I have connected it with USB-C to a Dell Laptop. This means that the laptop receives power directly from the screen and I don't need a charger. Also, thanks to the USB ports on the screen, I have connected all peripherals (camera, microphone, keyboard/mouse) directly to it. So, there is only one USB-C that connects the laptop to the screen and all peripherals. Tremendous convenience for a work from home setup, allowing you to have a completely clutter-free desk with easy cable management, few cables, etc.
- Also, very important is the flexibility of the screen's stand itself. The screen goes up and down, has tilt right/left, changes tilt up/down, and rotates vertically (unnecessary for the average user who won't put it vertically but it exists).
- Size: I consider 25'' with 2k resolution the golden ratio for office work on a typical (towards large) desk. At first, I was leaning towards 27'' but I'm glad I ended up with 25''. You can comfortably work in this size with 2 windows parallel, as if you have 2 screens.
- Connectivity: it can be connected with HDMI, DisplayPort, and USB-C. It has all 3 types of cables included in the box.

I am very satisfied that I ended up with this screen, after A LOT of research, searching through forums, sites with reviews, etc., and I recommend it with closed eyes. Its price is at the high end for a non-gaming screen, but for that money, you pay for the tremendous colors of the Ultrasharp and an amazing stand that deserves a review on its own, as well as tremendous connectivity.

Previous LG M2550D monitor, which has now been in use for a decade but continues to perform flawlessly. Photos edited in Lr over these 10 years truly show impressive and accurate colors on the Dell monitor. This, in my opinion, means that even the old monitor, properly calibrated (as much as possible), delivered very good and accurate colors.
Now let's move on to the Dell monitor, which I have had for less than 24 hours.
Excellent build quality, excellent stand, plenty of USB 3.0 ports. USB-C to USB-C, USB-C to USB-A-DP, power cables are included, but it lacks HDMI, which is a shame considering the price. Easy menu and controls, I recommend downloading and installing the display manager and driver.
I purchased it to connect to DEX mode with a Samsung S5e via USB-C. It worked immediately with the cable included in the package, but not with other USB-C cables that I already had. An ordinary Savio AK-47 hub, with a variety of ports, was connected to the USB-C port on the side of the monitor and worked perfectly. I should note that, for those who work with DEX, the hub was also connected to HDMI on the monitor and worked correctly.
I connected it to my old i3 laptop with an old HDMI cable, and Windows 10 immediately recognized the Dell monitor and adjusted the resolution accordingly. On restart, it automatically scaled to 120%, which I found excessive and changed it to 110%. I don't know if I will change it again.
Colors are impressive, as I mentioned, both in photos and videos. However, do not expect HDR video. The Vesa 400 HDR supported by the monitor has nothing to do with HDR on Netflix and YouTube, and Windows 10 does not recognize it as an HDR display. You can look into it, some accuse the company of "misleading" customers, and I don't think they are entirely wrong. Netflix shows FHD with both Windows and the S5e, and the image is satisfactory. In 1080p movies, the monitor reveals every compression and artifact, as it should, so it shows you exactly what you give it. In 4K YouTube videos, you will see the maximum quality that the monitor can deliver, and it is exceptional. However, I have an issue with video playback from YouTube, Vanced, and Netflix on the tablet because I only have the image on the monitor when I am in DEX mode. I would prefer the opposite, meaning video on the tablet screen and DEX on the monitor, but I believe it has to do with the settings I had already modified to have fullscreen Netflix on my old monitor.

For those who have or are considering purchasing a laptop with USB-C output and need an excellent monitor for photo and video editing at a reasonable price, the DELL U2520D is highly recommended!

(Since I have had it for less than 24 hours, if anything comes up, I will update the review.)

--- Update 14.02.2021 ---

In Windows 10, I have 2-3 windows open on the screen, using the Dell Display Manager, and I work comfortably. In SRGB mode with the buttons on the monitor or with DDM, I find the colors to be excellent, which has helped me a lot in photo editing in Lr.
When connected to the tablet, using a USB-C cable and in DEX mode, I found it convenient to have Netflix on the monitor and Android on the tablet. With the buttons on the monitor, I select movie mode, connect a 3.5mm Jack cable to both ends, connecting the audio output of the monitor to the T40II speakers' aux in, and I have sound there. The colors are excellent, and I didn't expect to enjoy a movie on a screen after experiencing the super AMOLED of the Samsung S5e, with a resolution of 2560x1440 and 30-bit color. Wonderful colors in movie mode!
However, I cannot say that the tablet cooperates with the monitor in terms of charging/power supply. There are some issues, it doesn't charge quickly (even though it's 90W) and it restarts if I unplug it in DEΧ mode. That's why I gave it minus 1 star.
On the back USB of the monitor, I have a 256GB USB stick permanently connected as an external drive for the tablet, and on the side USB-C, I have the hub with dongles for the mouse and keyboard. Incredible convenience.

--- update 02.10.2022 ---

The monitor is now connected to a Lenovo ThinkBook 14 G2 ARE, with the USB-C cable at 2560X1440 60HZ 30bit, the monitor provides power to the ThinkBook, one cable for everything, and all the USB ports on the monitor work properly, huge convenience, clean desk, and free ports on the laptop. Windows 11 recognizes the HDR400 capabilities of the monitor, which are not something impressive, of course.

Owner of the U2515H, I decided to purchase this specific monitor due to moving my old screen to another location. I hope that this review will help other users decide whether this monitor is suitable for them or not. I use it professionally for programming and video/photo editing, as well as AAA gaming whenever I have spare time.

-- Size/Distance/Angles: Personally, I consider 25" with 1440p resolution to be the perfect combination for someone sitting at a distance of 45 to 75 centimeters with 20/20 vision. It is comfortable, does not require scaling, and the pixel density is perfect, providing a clear and sharp image. It is worth noting that the coating on the panel helps with reflections without compromising the sharpness of the screen. The viewing angles are excellent, as expected from an IPS panel.

-- Colors/Calibration: I found the colors to be very beautiful, vibrant, and reasonably well calibrated by default. Thank goodness, it has an sRGB Emulation Mode with unlocked brightness (finally!), which works perfectly with slightly higher gamma. Without the sRGB Mode, there is some oversaturation, especially in the red tones, so I stick to the sRGB Mode. I haven't made any adjustments to the colors, and I operate the monitor at 70% brightness, which is already more than enough. I use Adobe Lightroom for photo editing as a hobby, and I have no complaints about color accuracy/coverage. I believe that this monitor is an excellent choice for photo editing and applications where proper color coverage is essential.

-- Contrast: We are talking about an IPS panel, so no one expects outstanding contrast and deep black colors. However, the contrast of this monitor is satisfactory and definitely better than other IPS panels.

-- Response Time/Input Lag: This panel left me speechless. The response time is significantly lower than the U2515H I had before, as well as the input lag. In general, I have never seen such a fast IPS panel at this price range, and I would say it is possibly the fastest among all the Dell Ultrasharp series so far. This means that the monitor is a good choice even for casual gaming and scenes with fast movement.

-- Overclocking: Another pleasant surprise is the panel's ability to be overclocked from 60Hz to 75Hz without frame skipping. I don't know if this applies to every panel of this specific model or if I was just lucky, but I assume that since the panel is the same in every U2520D model, the capabilities for +15Hz OC should be the same. The difference in motion smoothness is noticeable even by simply moving a window in Windows, even if it's just +15Hz. Even more so in games. Considering that someone can maintain 75FPS+ in games, I think it is a beautiful bonus of the monitor, offering good gaming features (low response time, low input lag, 75Hz) on a non-gaming monitor. Personally, with VSYNC ON in Ultra Low Latency (since I hate screen tearing) and +15Hz OC from the Nvidia Control Panel, at 1440p with this response time/input lag, this monitor is excellent for gaming.

-- USB C / Dell XPS 15 9560: The connection worked flawlessly with my laptop, without any issues with power supply. -- IPS Glow / Backlight Bleeding: Both are present. IPS glow is a common characteristic of all IPS panels, so either you tolerate and get used to it or switch to TN/VA panels, there is no other solution or fix, it is what it is. Personally, it doesn't bother me, and as long as you view the screen directly from the front, and not from an angle (top, bottom, left, right, etc.), the glow is barely noticeable. There was minimal backlight bleed in the bottom left corner of the screen, which was not particularly bothersome, and I would have to be in a pitch-black room with a black background on the screen to notice it. I would not recommend this monitor for someone who wants to watch movies in a dark room.

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** UPDATE (01/12/2021): Unfortunately, a few months ago, the monitor started making a high-frequency noise, essentially something like coil whine but with a very high frequency, when the brightness was below 100%. At 100%, it completely stops, but the brightness is quite high for extended use. I have been searching for a solution for months, as other Dell models have the exact same issue, without success. Dell's tech support is useless, with solutions like "keep the brightness at 100% and lower the contrast". Yeah, okay... goodnight. If you can work with everything at 100%, then all is well, otherwise either you will never notice the sound, or you will get used to it, or you go buy a new monitor.

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** UPDATE (21/11/2022): And yet, I am still here, with the U2520D :) Working at 100% brightness, and surprisingly, I haven't had any issues, yet. It's hard to part with a monitor that does everything so well.

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** TLDR: An excellent monitor, albeit a bit pricey, it is bright, with beautiful colors, comfortable and fast, suitable for professional use, office work, video/photo editing, and even casual gaming. Clearly an upgrade compared to the U2515H in every aspect.