I'm looking at purchasing a new iMac for home use; the more and more I read and research though I keep second guessing myself as to what would be best for my needs. I'm currently in my last year of masters in aerospace engineering and am also planning on doing a doctorate next year; my current work involves heavy use of Matlab (dealing primarily with fluid dynamics) as well as programming in C/C++ in Xcode. The work side of things also involves the use of office and tex based programs. Leisure wise I like to play the occasional simulation and strategy game (usually something like the sims, red alert, x-plane or train simulator....lol yes, train simulator... sometimes a fps, maybe call of duty 4 or warsow - suffice to say, not really a big computer gamer); I also like to occasionally edit videos/work on effects as a hobby (using FCS & iMovie, After Effects, Blender, and Gimp). Aside from those specific uses, I also use the regulars, internet, email, iphoto, music, etc. I was using a 2008 24" 3.06Ghz Core 2 Duo with 4GB of Ram and for the most part it was alright, although not the fastest thing in the world. Now, I personally am thinking that to cover all my bases I could easily grab the refurb/new 2010 27" i7/i5 or refurb 2009 27" i7/i5; however, do any of you think I'd be good for the next several years with any of the i3 models? Or perhaps the 21.5" with the i5 with the ram upgraded afterwards? The big screen is tempting and I liked the 24" size but I'm wondering whether its really worth it for my uses. I'm hoping to have this machine for the remainder of my masters as well as for my doctoral studies.