I know how you feel when you get "that feeling" about a car. My old TT was great at first, then the MAf went, then the coil packs went, then the dashpod went, then the heated seats burned my arse etc..etc.. Was a proper lemon and I needed to change it to feel better.
Maybe a change is a good idea, who knows you may drive summit else for a year or two and then come back the the fray if/when BMW pull their finger out and sort some of the issues out.
Whichever way you go though, don't worry about the negativity, a lot of us are a bit fed up at the moment, either with the car or with the roads... can totally relate to the instant feeling of wanting a change as soon as you hit a pothole!