I am on the verge of springing for a 20" iMac. However, I'm trying to carefully weigh the performance of the 2.4 versus the 2.66 model. The local stores seem to keep their 2.4 display models pretty crippled. However, they load the 2.66 ones pretty well and they run great. I'm concerned about real world performance and whether the 2.66 is really worth the extra 250 dollars. That money could well be spent on more ram or put in the bank. I'm upgrading from a c2d mini so either video card will be a huge improvement. I've seen benchmarks comparing the two, but they seem to focus on first person shooters. Would the 2.4 be capable of running x-plane with any degree of success? Are there any 2.4 owners out there who have regrets and wish they had gotten the faster card and chip? Thanks for the help.