I've owned my 13" rMBP for the past 2 years. It's a great little machine for what it is, though I'm finding it hard to use as my only computer, as much as I'd like. The truth is, when I switch over to any decently fast Windows PC build, it's a little night and day. Here are the reasons I don't think the 13" should even bear the "Pro" name, but rather just a souped up MacBook Air. The 13" rMBP in my opinion is basically the Retina MacBook Air people have always been asking for (and it's only $300 more which makes sense). 1. No quad-core option 2. No option for > 8GB unless you want to drive the price up to as much as a 15" rMBP, at which point why not just get the 15"? (RAM is not really an issue for me - but I still find the pricing and options to be wacky) 3. No dedicated GPU option 4. Laggy OSX animations up until this point (El Capitan may introduce serious improvements, but 2-3 years later?). In general, integrated graphics are crap we all know that. But it doesn't help that it's having to power so many pixels running on a less than optimized operating system for graphics. In conclusion, I believe the "Pro" label for the 13" is a misnomer. The 15" doesn't suffer from any of the drawbacks that the 13" does except for still some occasional GUI lag. Don't get me wrong, my 13" has been great and does basically everything I want it to. I just don't know if I'd consider one for my next computer when I feel it's mis-marketed.