I'm looking at the new Haswell rMBPs but I am trying to justify the extra cost of the 15" with the dedicated nVidia card over the top spec 13" without one. My primary use is HD video editing and rendering. Quite simply, will a too spec i7 dual core 16GB 13" rMBP "do the job"? Most of the footage I edit is shot in 2.5k and I'd like to be able to edit in FCPX as close to this resolution as possible without it being a tedious and slow process. I use an external color grading monitor so the size if the screen on the rMBP does not matter. Is a dual core i7 enough "juice" to edit in 2k+ resolution for a smooth experience? Does the dedicated nVidia card really provide a much better experience and justify the extra cost?