After many weeks trying to decide which model rMBP to go for I have narrowed it down to the top end 13" retina model, upgraded to 16GB RAM or the bottom end 15" model as it is. My total maximum budget that I have stretched to is £1500 and both these come in at just under that. I have a powerful quad core Hackintosh with dedicated GPU for all my heavy video and photo editing, so will only use the Macbook for mostly general use (web, iPhoto, email, iTunes) but I do want to be able to run Photoshop and iMovie efficiently (nothing too intensive, only a few photos open at once and basic video editing) The 13" is preferable for it's size and portability if its up to handling these tasks. I would definitely make use of the 512GB storage but its not essential, and I think having 16GB RAM for what I need it for is more a case of future proofing than a necessity so I can't fight the feeling that I'm probably better off with 8GB in the 15" and getting the benefit of a quad core CPU and the Iris Pro graphics. Any opinions welcome, sorry if this has been discussed before, I did do a search but most comparisons seemed to be the age old 8GB vs 16GB.