If you have the room go with the 27", you get used to the size, it is hard for me to switch back to my PC with the 21" screen after using the Imac.
The problem with that is that the 27" looks much smaller in the store than it will be in my small roomI came across the same question, I sold my 24in recently but when I went to apple store and saw 21.5in and 27in, 21 was too small if u have used a 24in iMac so I ordered a 27in now they will be delivering in a few days,, very excited!!!!!
I also just changed from a 24" to 21.5" and my "prob" is not the size of the monitor itself but the resolution. I miss the space I had on my desktop
Why is the 21.5 limited to 1920*1080 ? Is it the gpu ?
Because of this there is less space on the desktop compared to the bigger screen plus higher res
Having only wanting to get a 27" at first, I've decided to get the 21" in the end, after a LONG time deciding, heres why:
the 21" has more of a traditional desktop computer experience
the 27" is just a monster, its too extreme..its like a TV/workhorse for editing/zooming/cad/coding/having lots of
things opened at once, as many people have noted they seldom use the space
it is overwhelming, you can't sit close to it, and if you have a smaller room it looks way too big in it.
you have to turn your head side to side and drag the mouse a lot to get to things
everything looks tiny on the 27" the pics, the videos, icons on webpages etc etc and was giving me eye fatigue after 10 minutes of use, its just not a computer for casual everyday use