I'm new to the forum but I currently have a 13" MB. I'm looking to upgrade to a MBP but I'm not sure which one to get. I need the 15" because I will need to take it with me to work. Now, I can't decide between the two 15". I will be doing Video editing on the machine for work. I was thinking I would need the higher end one but all the Imacs at work are the lower end 20" ones (256 graphics card). There are also several mac pro's and last gen MBP (256). The Imacs and MBP handle the video work just fine, so guess my question is, do I really need the higher end one? Does the L3 cache make a difference? Since the other macs at work only have 256 graphics cards but they work perfectly fine, will I need the 512? Thanks.