My late-2013 15" rMBP (2.6Ghz/512MB/16GB) was 99% perfect. Great display, no issues with it from a functional point of view--just a bit of Mavericks-related flakiness here and there. But it had one physical "quirk" that was beginning to drive me completely insane. It seems that whenever the computer would heat up a bit, the aluminum chassis would flex or warp very slightly, resulting in the trackpad feeling just slightly loose and making a subtle "ticking" sound every time I touched it. It was like this from day one. This was the kind of thing most people wouldn't notice, but given that I use my computer in a very quiet studio a lot of the time, it eventually got to the point where that ticking sound felt like the loudest noise in the room, and I found myself trying to alter my hand position or touch the trackpad in a particular way so as to avoid hearing it. That was no fun. Keeping my expectations low--albeit with the tacit understanding that I was entitled to be taken seriously after dropping ~$2500 on a computer--I took it to my local Apple store (Oakridge Centre, Vancouver, for the record). The friendly Genius was frank, telling me that the only cure--replacing the entire bottom chassis assembly (including battery + trackpad)--was a bit extreme for a problem that didn't affect the computer's functionality. "But that said, we take fit and finish pretty seriously here," he added. 24 hours later, my rMBP is now 100% perfect--in addition to having a brand new battery, trackpad, and bottom chassis. Long story short, I may not agree with everything they do, but so long as Apple can maintain that level of customer support, I'll be sticking around.