I find it kind of amusing how the Rocket folks argue performance over aesthetics every time Harleys are brought up. Yet when German bikes are mentioned, suddenly its aesthetics over engineering. I don't recall Rockets winning any beauty contests.
Having owned five BMW motorcycles, a 3 series, a Mini, a VW GTI, and a Golf R, I'm kind of fond of German engineering. They do occasionally slip up on execution but I've never had a problem with any of mine. If the rumored BMW fits someone's riding style, I doubt there will be a better made machine for the purpose.