I just bought the MacPro 2.66 gHz. Haven't tried games, but it handles video, audio great, no lag. Quiet too. I haven't run a comparison, but I couldn't imagine 3 gHz would offer such a big performance difference to be worth $800 more. Probably dropping a little more ram into a 2.66 will give you better performance than pumping up to a 3 gHz, and you can double the gig of ram it comes with for under $400. Just MHO.