I'm upgrading from a 13" rMBP to a 15" rMBP w/ 16GB SDRAM. I had a 512GB SSD in the 13" and a 256GB SSD in the 15", so I decided to swap the SSD's since I'm keeping the 15" and trying to sell the 13". Since these are two different models of the rMBP, I was all ready to do a full factory restore after the swap, but then I booted the 15" rMBP and it booted just fine. Checking system information, system settings, etc... everything seems to be working right and recognizing the right hardware. Same for the 13". I had to re-authorize my iTunes, but that wasn't a big deal (and I was able to de-authorize my account from the 13" after the swap). I'm pleasantly surprised that it all worked so easily. Does anyone know any reason why I should do a full restore?