Hi all, So, we're going to purchase a new 15" MBP. We use it for a lot of media creation (recording music and such). We're looking at the i7 processor, but wondering if we woudl notice much of a difference between the 2.66 ghz and the 2.8 ghz processor. Is the difference pretty negligible? Also, apple wants to charge $400 to upgrade to 8 gig of RAM? What? Is it that how much 4 extra gigs of RAM cost? Or is that the "apple tax"? Is it hard to add the ram yourself? Thanks for any insight!