I've been going back and forth between the 13" and 15" rMBP. I don't really need the extra performance of the 15", but like the larger display. After playing with both models, I decided to get the 13" because, for me, it offers the best comprise between performance and portability. The factor that made my decision was the ability to scale the resolution of the 13" to 1440x900 (the same as the 15" MBP I'm replacing). I'm getting the same exact screen real estate I've used for years in a much smaller package. Has anyone run into problems with performance when scaling in this way? Is there any advantage to using the native resolution? I understand that it might be "clearer", but to be honest, I can't tell a difference in clarity between native and scaled.