I am in school learning to program for Xcode. I have a 21.5" iMac (Base) and 11" MBA (2nd tier), both are 2011 models. I also have an iPad 1 and 2. My primary issue is that I don't want unnecessary overlap, but I also want to have a 27" screen. I was considering selling the iMac for a 27" Thunderbolt ACD and using the Air with that. Would the Air be enough? Would a MBP be better suited with an ACD to pair it with? Or, I could upgrade to a 27" iMac. Having two separate computers is appealing (versus 1 laptop and an ACD) *note, I'm thinking maybe the iPad 3's hiRes screen will be another solution, to use for viewing pdf's and freeing up my screen real estate like I do now (its just not super sharp or fast and is a bit of a pain now) Any thoughts on your own set up's? Or advice for mine? Thanks!