Between the base model of the 27" iMac and the top of the line, there are $ 400 difference. For the past several days I've been hunting high and low for answers, but it's hard to talk to "regular" people because most just look at me weird and say "Get a PC. They're cheaper." Or I talk to someone at the Apple Store and they tell me (obviously) to get the top of the line. I own an early 2009 24" 2.9MHz Intel Core 2 Duo iMac that currently has 8 GB RAM. I use it mainly for Adobe (InDesign, Illustrator and Photoshop) for work, and for image post processing (Aperture, Photoshop) for a hobby. It still works fairly well, but mostly Aperture is giving me problems with the stuff I'm throwing at it. Plus, my son really would like me to upgrade so he can have my present rig. I'm worried about spending too much for a setup I don't need, but I'm worried also to spend too little and be sorry in two years when Adobe pushed yet another updated to their programs and I'm lagging behind with hardware. I suppose nobody can make the decision for me, but I would appreciate all the help I can get.