Just wondering how many years most designers expect to get out of their main work machine between upgrades? 2 years? 3 years? 4 Years+? Basically my 2.33ghz MBP (3gb ram) is approaching the 3 year point in november here and it's starting to feel long in the tooth. I'm currently debating if it's worth while to upgrade the internal drive to a 7200rpm HD and hope the performance increase will tide me over for another year, or if I should pull the trigger on a new machine. Truth be told looking at apple's current crop of laptops there is nothing I would consider to be a "huge" upgrade from what I currently have. The only machine that's really appeals to me right now is a refurb 3.06GHz iMac. But given that I already have a 20" cinema display it seems redundant to buy an all in one mac at this point. So whatta say Macrumors?