Hi, I'm upgrading this month from a 2009 13" Macbook Pro, with a 2.26 Core 2 Duo and a Geforce 9400m, to a new 2.2 i7 Sandy Bridge Macbook pro 15". Obviously I'll experience plenty of processor and graphics performance upgrade, as well as a huge screen and HDD space boost, however here's my question: From 4g's of 1067 memory to 8gs of 133 memory, will I notice a difference while using programs like: itunes, safari, photoshop, preview, and photoshop all at once? gaming and itunes + skype? photoshop and iphoto? imovie and itunes? Will I even notice this difference? I have plenty of money, however I simply wonder whether it'd be worth it, aside from having apple upgrade with their memory package, which I'd rather have them do.