Any recommendations on what to look for as far as compatibility with my current and future MB Pro?
You can use it with the 2010 MBPro
@1080p.
I have a Dell S2817Q 28" 4k display (it was cheap - I'd only consider it for extra real-estate, the colour isn't up to photo editing - but the observations may apply to other Dell displays) - which I've tried connecting to both a 2010 Core 2 Duo 13" MBP (OS X 10.9) and a 2011 17" MBP (MacOS 10.12). Some observations:
1. With a MiniDP-to-DisplayPort cable, I just get a blank screen (on both the 2010 and 2011 MBPs). However, I found that a StarTech
active MiniDP-to-HDMI adapter works. (
https://www.amazon.co.uk/dp/B00LV9SWE0/ref=pe_1909131_77697121_tnp_email_TE_AMZLdp_1)
2. Works at 2560x1440, 1920x1080 and 4k native 3840x2160 (yes, even the 2010) - but the latter is only 30Hz and you get very small text & icons... I haven't tried to use it in anger on the 2010 to see what the lag is like!
3. Had a bit of crashiness and weirdness on the 2010 with the 4k display connected... and after I select "1080p" many of the other resolution options mysteriously vanish... may be an OS X 10.9 thing...
4. You can drive most 4k displays in "Scaled" mode at 1080p or 2560x1440 from a non-retina, but the quality is not quite up to what you'd get on a "native" 1080p or 1440p display - but its the monitor doing the scaling and the result is a bit "soft focus". Its not
bad but it would be rather disappointing if you'd just bought a new display. (On a retina-capable Mac, Scaled modes render internally in pixel-doubled mode and then
downsample to 4k, using the GPU, and the quality is in a different league).
Overall, I'd only get a 4k display for a 2010 MBP
if I were on the brink of upgrading to a retina-capable machine but desperately needed a larger screen in the interim - the 2010 MBP deserves some kind of medal for even supporting 3840x2160 and its of limited practical use, the display quality at 1440p is usable, but disappointing, and 1080p text & icons are too big for a 27" display.
My advice would be to either:
(a) Make do without until you upgrade, and don't let the need to work with an old Mac constrain your choices of new display when you do upgrade.
OR
(b) Get a "native" 2560x1440 display - which will work more smoothly with your old Mac, give a better-quality image at 1440p, and still be perfectly usable with any new Mac you buy - just not 4k.