And I'm using the word "required" very loosely. My wife is doing a lot of photo editing in Lightroom (and eventually in Photoshop) for our start-up business. We are going to be buying a new macbook. My brother-in-law (a techy) told us that we would need to get a mb with a GPU for it to run properly (which knocks out the MBA and 13" MBP). Then he also said that if the GPU has less than 500MB of memory we are "basically wasting our money" which would leave us requiring the $2,200 15" MBP (or any iMac, which may become an option). I was hoping to buy the $1,500 13" MBP (probably after the next refresh, because there is no immediate need), but do you guys really think it would be worth that much more to spend an extra $700? How much better would these editing programs really run with a GPU? Again, she will mostly be doing editing in Lightroom with some minor work in Photoshop (say for content-aware deletion).