I just received the UltraFine 4K display and it is just amazing! The uniformity and colors are perfect. No dead pixels, no retention issues and no problem with waking up from sleep. The only thing that needs to be fixed is the volume - the step from one bar to two bars is too big. Maybe they can fix this with an update. But the sound quality is actually pretty impressive from the built-in speakers. I use it with the 13-inch MacBook Pro 2016 with touch bar and mainly use it for web and app design. I would have loved the 27-inch but my workspace at home is rather small and the 21.5-inch model is a perfect fit. It is much more easy on the eyes - and I don't have to turn my head from side to side when using the display. So I am really impressed with the UltraFine displays. They are expensive but well worth the money.