I bought the 21,5" iMac last week and my friend a 27". When we where playing together, I noticed the 27" display is much sharper. Even my girlfriend could see this within one guess. It could be a psychic thing, but every time I am behind my 21,5" I see a screen with could be sharper. Even my Macbook 13" is sharper in my opinion. Do the 21,5"/27"screens come out of the same manufacturer with the same specs or is there a quality-difference??