Sometime soon, I'm planning an upgrade from my Mid2012 MacBook Air to a Retina MacBook Pro. I've been getting more into photography, and think an upgrade would be greatly appreciated. While I don't have great difficulty with processing photos on the Air, I've found that screen real estate and hard drive space are not the best. My question is this: Should I go for a mid-range 13" retina, or should I go for the base model 15" retina? The most compelling pro of the 13" model is the portability of the unit -- easier to travel with. Frankly, I don't travel that much, but when I do I find that I us the iPad during the flight as it is -- even opening the 13" MBA is frustrating in the tiny amount of space they give you mid-flight. So, have at it. I'd like to hear the pros and cons of going both ways.