Hi everybody! I am a long time reader, first time poster. I thought it was time to give something back to the community 
Short disclaimer: This is all my personal opinion. But I am trying to be as balanced as possible.
I bought the 21.5 inch 3.2 Ghz, RadeonHD5670 iMac 3 days ago and I wanted to share my impressions because I think this will bring peace of mind to many and save you money.
I was obsessing over whether or not to buy the 27 inch version, mainly because of the better graphics card. Now that I have the 21.5 inch iMac I am very, very happy with my choice.
Now, let me tell you about my computing needs: Office, TeX, internet, email, skype, iphoneSDK, Handbrake, rarely some Matlab (when not in the office or working remotely), Photoshop (to work on my DSLR photos) and some gaming. Everything runs perfectly, snappy, fast! As expected.
The screen's 1920x1080 resolution is more than enough. Reading news online or documents is a pleasure. The color and viewing angle are amazing. HD movies (tried some trailers) look great. You can still sit at a reasonable distance and watch a movie with your friends. the 21.5 inched suffice. In addition, personally I believe that in a smaller room on a regular desk the 27" iMac is just too big.
My machine has an i3 3.2 Ghz processor and 4 GB of RAM. All the programs above run great, even with internet, email and skype open all the time. No i5 or i7 needed! I guess the only thing justifying an i5 or i7 would be hadr-core video encoding. But I am not an expert on this. For the occasional home movie form the holidays my machine should still cut it.
And now about gaming. I know this is a big deal to most. I used to play a lot of games when I was at school but at uni and now that I work I don't have the time to play everything. My priorities are Starcraft2, Civilzation5 and Diablo3. Now, chances are that there are a lot of likeminded people out there. People who like games but prioritize because they don't have so much time, other hobbies, a wife or girl/boy friend, work etc - you name it.
Rest assured! This machine is all you need. I run Starcraft2 in bootcamp under win XP. It runs very smooth in the 1920x1080 native resolution and everything set to HIGH exept the postprocessing (which is un medium). I haven't even tried out higher settings yet because the game looks so awesome. I will play it for years to come. Civilization 5 is coming out tomorrow and my iMac matches (or is above) the recommended system requirements, so no problem there. And judging from the gameplay videos of Diablo 3 - making an educated guess - it will run more than adequately on medium settings, maybe even on high.
So to sum up. If you have similar gaming requirements as me, then go ahead and buy the i3 - 3.2 Ghz iMac. You will not regret it. Don't fall for the marketing hype. One does not always need the high-end machine. Get this machine, save the extra money and enjoy the peace of mind
Hope this settles the 21 vs 27 issue for some of you.
Short disclaimer: This is all my personal opinion. But I am trying to be as balanced as possible.
I bought the 21.5 inch 3.2 Ghz, RadeonHD5670 iMac 3 days ago and I wanted to share my impressions because I think this will bring peace of mind to many and save you money.
I was obsessing over whether or not to buy the 27 inch version, mainly because of the better graphics card. Now that I have the 21.5 inch iMac I am very, very happy with my choice.
Now, let me tell you about my computing needs: Office, TeX, internet, email, skype, iphoneSDK, Handbrake, rarely some Matlab (when not in the office or working remotely), Photoshop (to work on my DSLR photos) and some gaming. Everything runs perfectly, snappy, fast! As expected.
The screen's 1920x1080 resolution is more than enough. Reading news online or documents is a pleasure. The color and viewing angle are amazing. HD movies (tried some trailers) look great. You can still sit at a reasonable distance and watch a movie with your friends. the 21.5 inched suffice. In addition, personally I believe that in a smaller room on a regular desk the 27" iMac is just too big.
My machine has an i3 3.2 Ghz processor and 4 GB of RAM. All the programs above run great, even with internet, email and skype open all the time. No i5 or i7 needed! I guess the only thing justifying an i5 or i7 would be hadr-core video encoding. But I am not an expert on this. For the occasional home movie form the holidays my machine should still cut it.
And now about gaming. I know this is a big deal to most. I used to play a lot of games when I was at school but at uni and now that I work I don't have the time to play everything. My priorities are Starcraft2, Civilzation5 and Diablo3. Now, chances are that there are a lot of likeminded people out there. People who like games but prioritize because they don't have so much time, other hobbies, a wife or girl/boy friend, work etc - you name it.
Rest assured! This machine is all you need. I run Starcraft2 in bootcamp under win XP. It runs very smooth in the 1920x1080 native resolution and everything set to HIGH exept the postprocessing (which is un medium). I haven't even tried out higher settings yet because the game looks so awesome. I will play it for years to come. Civilization 5 is coming out tomorrow and my iMac matches (or is above) the recommended system requirements, so no problem there. And judging from the gameplay videos of Diablo 3 - making an educated guess - it will run more than adequately on medium settings, maybe even on high.
So to sum up. If you have similar gaming requirements as me, then go ahead and buy the i3 - 3.2 Ghz iMac. You will not regret it. Don't fall for the marketing hype. One does not always need the high-end machine. Get this machine, save the extra money and enjoy the peace of mind
Hope this settles the 21 vs 27 issue for some of you.