You can "get used to" just about anything, but why should you?
In this case, you shouldn't let anyone decide for you - it's your eyes and your body.
Well said.
I tried four 27" i7 iMacs at the beginning of the year but returned them because of the yellow display issues. I had to go back to my old 20" iMac which was horrible at first but after a few hours I was used to it again, and haven't missed the 27" that much (well, missed the speed of course).
I'm now considering the 21.5" iMac, for having a more compact (focused?) machine. Just wish I knew for sure they have no screen issues.