Hi guys, I know that Apple recently gave the MBP line a speed bump. I'm in the market for a new 15" rMBP. I had a friend offer to sell me his "previous generation" one. The specs are the same as what I would buy (2.7ghz, i7 Processor, 768 GB SSD, 16 GB RAM). Here's my question. When Apple released the latest update, did anything else improve? Is there ANY difference between a 2.7gzh model in this generation and the previous one? I've looked everywhere and can't really find any details. Thanks guys!