Moving to an rMBP, and wondering if I really need to shell out for the top spec model with discrete graphics. I currently do a lot of Photoshop, a little bit of CAD (only on sketchup) and next year I will be producing a short documentary on FCP as part of my Uni work. I'd really like the portability of a 13", as well as the obvious cash saving, so I was thinking of going for the maxed out 13 as opposed to the 15". Do you guys reckon this will be fast enough for my needs? (Display size isn't too much of an issue as when I do editing I'll most likely be using a secondary display). Will it handle everything I want it to, or do I really need the discrete GPU? Cheers for any help.