Summary: Movies and photos look fantastic, and it offers a slew of I/O ports and a fully adjustable stand. That said, it's limited to a 30Hz refresh rate in UHD mode, which will likely disappoint the gaming crowd, and its color accuracy is a tad off. The Acer B286HK also exhibits slightly skewed greens but it can display UHD content at 60Hz and offers a speedy 2-millisecond (gray-to-gray) pixel response and a robust feature set.
It's not that bad if you know what you are getting into
F. Lin, Amazon
3 weeks ago
Summary: Bought one refurbished for $220 including tax & shipping. Yes there is a delay but after a couple of days your eyes will get used to it. You are able to display so many applications and windows which makes work much more productive. Gaming is not great but playable as long as it's not first person shooter. I played Diablo 3 at 4k resolution which is quite an eye treat, just don't expect to break your greater rift record.
Summary: It's only 30hz at 3840x2160 (4k). So that's basically worthless. I run it at 2560x1440 (which is plenty of resolution for video editing) at 60hz. Even that feels a bit laggy, but for my purposes it's fine. Not a gaming monitor by any means. Image looks great.
Summary: This Dell Monitor is a well-equipped 28-inch Ultra-High-Definition (UHD) monitor that delivers a highly detailed 4K image, but it can't do it at 60Hz. Pros: + Affordable. + Sharp UHD image. + Generous feature set. Cons: - UHD only works at 30Hz. - Narrow viewing angles.
Summary: Looks good both in picture and design. Mouse lag IS a massive issue. I'm not sure why some people claim that there is no mouse lag. There clearly is, even for someone who just surfs the internet (as opposed to a gamer). I think some people just don't see the lag but Dell clearly admits the lag is present and unfixable: -Due to the hardware architecture, the mouse lag is a result of the P2815Q requiring 100ms to process video data.
This is a brilliant external monitor for people who have loads of browser ...
Amazon Customer, Amazon
19 January 2015
Summary: This is a brilliant external monitor for people who have loads of browser tabs/windows, or lots of concurrent programs open. Because it runs at only 30Mhz refresh rate irrespective of resolution, there is definitely a lag when moving a mouse around on it, and its not suitable for gaming. However, the colors are great, text at either full resolution (3840x2160) or at a reduced (2048x1152) is crisp and readable.
Summary: It's not as bad as some are saying. I lowered the gamma setting on my video card and having done so the black level on the monitor is fantastic. Good contrast. Sharp picture. Nice and bright without being washed out. Yes, it has a 30 Hz refresh rate at max resolution. It's not so bad. I got mine refurbished from Dell. I'm happy with it.