I currently have a TOTL 2012 rMPB. It has served me well, but frankly I am tired of lugging it around as I work in the field a lot. I use Autocad LT and VMWare pretty much all the time when working. I have resisted moving to the 13" rMBP as I am always worried about going backwards in performance. The problem with the 15" is that whenever AutoCad LT or Fusion is opened it reverts to the discrete graphics and the battery life suffers greatly. I had a 13" MBA before the 15, but used 17" MBP's before that Air. I just bought a 13" for a coworker and so far he is fine. It does bug me that none of the local B&M Apple stores carry any of the 13" rMBPs in 16GB. Though I originally thought that I was having issues with memory affecting battery life, I think it's more related to the video card switching. I find it goes to the discrete more often than I thought. I'm just curious what folks experience is going backwards in performance.