I don't want to open a giant can of worms, but the statement that you have to be closer than 2 feet to see any difference with a 27" screen is based on an assumption about the visual acuity of the human eye, and let's just say that assumption isn't universally accepted.
I've seen both still and moving images 4k side by side versus 1080 and, although they weren't on 27" monitors, I came away feeling that 4K delivered an advantage even though it was beyond the theoretical visual acuity limits. However, I should also say that the advantage was very very small, and furthermore it's probably more relevant to gamers or movie viewers than to still image editors.
For still image editing I'd suggest colour fidelity, wide gamuts, calibration, consistency right across the screen and other factors all trump absolute resolution, so I'd still be inclined to go with the Eizo, just not for the reasons you suggest!
Incidentally, I'm also wrestling with a monitor upgrade, but one factor I'm unsure about is the practicality of using a 4k screen for general web browsing? However all things considered right now, like you, I'm veering towards the CG276 or CG277, so if we're wrong at least we'll be wrong together!