I'm planning to finally get a new desktop in the near future to replace my aging G5, and it's almost certain to be a 27" iMac. The only serious question in my mind is which processor to get, given that the resource intensive application on this machine is going to be Aperture? My library is currently around 250 GB and growing, containing a mixture of 10 megapixel RAW files and 23 megapixel PNGs (I also have a film scanner), and it's not unusual for me to import several GB of images at a time, and then do a bunch of editing. For most things, my inclination would be to go with the low end model. In particular, paying $300 for a 15% clock speed bump (3.1 GHz versus 2.7 GHz) seems like it's probably not a great deal. But for $500 above the base model, there's the i7, with hyperthreading, which could potentially make a much bigger difference. The numbers here suggest that I'd only see about a 10% difference in performance between the low end and high end models, which means I should save my money for an SSD (which I plan on getting once they and Thunderbolt enclosures for them get a bit cheaper -- I expect that in a year or two that will be a lot less expensive than the current Apple option). But I'm still curious to hear other people's thoughts and experiences, since those numbers are just one specific test. The only other question is whether to upgrade the HDD from 1 TB to 2 TB. Again, ordinarily I would stick with the base option and upgrade later when I actually need the space, but given how annoying the current iMacs reportedly are to open up, I'm not going to want to do that. I could probably just use ThunderBolt for that, too, though, since I probably won't need the extra space for another few years; the major question is how much is it worth not to have extra things cluttering up my desk.