Best you can get today?
For my Mac Pro I went with a 24" Dell UP2414Q 4k display. 4k at larger sizes than 24" is just awkward: pixels too big to use at 2x, too small for 1x. But this Dell is just the right size to be a Retina display that works TODAY.
It looks terrific! And it has nice scaling options just like a retina MacBook Pro. No software to install--Apple supports this model specifically with scaling options not found on larger 4k displays.
However... you get what you pay for with Dell. Styling-wise this is not Dell's worst (clearly imitating the 2007 black-and-aluminum iMac design), but it is NOT close to Apple's display standards:
- No camera, no mic, no speakers, no Thunderbolt hub, audio ports, Ethernet, etc.; no powered USB, just an unpowered USB hub that loses power when the display isn't on.
- No option to adjust brightness automatically with an ambient light sensor. (Didn't realize how much I'd miss that.)
- Won't reliably wake from sleep!! And when it does wake, sometimes you get only half the screen. Keep trying.
- A few little bits of hair or dust between the layers. Looks like dead pixels, but it's not.
- Cheap painted silver plastic, combined with a few not-quite-matching thin panels of real aluminum.
- Gaps and cracks and creaks and flexes. Just feels cheap.
- Awkward touch controls that don't always work. Sometimes you have to press hard. Simply adjusting the brightness is a pain.
- Unreliable sensor that makes the controls' lights blink annoyingly.
- No protective glass--and thus risky and difficult to clean, and easy to bash with a box corner.
- Can't respond to the brightness keys on my keyboard.
- Shipped at an awful 30Hz and took research and hoop-jumping to enable 60Hz.
- Good warranty that might help with some of the above... except it's unbearably painful to deal with their support staff. Good luck with that.
- No magsafe to power your Mac laptop. This is not a dock for a MacBook the way Apple displays can function; but that's OK with a Mac Pro.
- Not a great black level, and uneven glowing backlight bleed around the edges when viewing dark images. Viewing angle is OK, not great.
- Generates a TON of heat! Ouch! My electric bill!
- Sits on a permanent, very slight diagonal in landscape (normal) mode: the portrait–landscape pivot won't quite rotate all the way to level.
But yet... when viewed head-on, it has awesome res and color! I'm glad I have it--there is no better option yet. Also, it goes to Portrait... sometimes. And it can go very bright! And if you play endless games looking for deals like I did, you can find a cheap price. (Or you can get sent the wrong thing and waste time and end up not getting such a good price... like I did.)
I use mine at a scaled res equivalent to 2304x1296. But it will go as high as 3008x1692 if you like to squint.