Check out this two part video about how different high res video options compare to each other at real resolution.
(plays in browser windows, so just click part 1 and part 2) Part 1 is the 6 different cameras compared to each other in multiple scenes (its 4k so be patient) and part 2 is Steve Yedlin, the creator, explaining everything in some solid detail.
http://yedlin.net/ResDemo/
This is basically solely focused on a cinema experience, the guy makes some interesting points about 2k, 4k, and 6k, how we actually perceive them, I was quite fascinated by it, enjoy!