IMac :: 27" Display No Longer Huge

I remember when the late 2009 iMacs debuted and I went to the Apple Store to check them out. At the time, I thought the 21.5" was just the right size, while the 27" was monstrously large. I had a couple friends try to talk me out of the 27, saying that it was simply too big for home use.

Fortunately, I let the nerd in me out and got the 27. And after only a week of using it, the size no longer impressed me the way that it used to. Suddenly 27 was only normal, while the 21.5 became miniscule. Which made me think, just how big can desktop displays go before they're really "too big"? 30? 34? 40?

Is there even such a thing as "too big"? Or will we just adapt to the larger size like we've been doing all these years?