Just a conjecture, but these engines really don't seem happy if they are "lugged" at all, so driving style may play into the issues some are having. And the factory ECU tune doesn't seem to help either. On my 2012, I replaced the ECU almost immediately with an unlocked unit and removed the cats (after one self destructed), and after allowing the engine to auto tune the fuel then saving as a new baseline a few times, the engine seems much happier, smoother, and definitely cooler than the before state.
Of course there is also the very real possibility that S&S's quality control wasn't exactly world class....
