I"ve got a 1 1, and i've basically just been offered £425 quid for it (I paid 300 a few months ago) , so i'm making money there. I've been offered a 3,1 for £500, so a £75 quid upgrade. Aside from running Mavericks, how much of a noticeable boost is there? I don't care about benchmarks, id like to hear from people who are actually using the machines, I'll be throwing and SSD in it, and probably go to 8 or 10gb of RAM. Its a baseline 2.8 machine. Is it worth it? or worth saving and getting a 4,1 or newer?