Oddly enough I've never gotten any comments on my 135 convertible that were negative at all. Nothing along the lines of "couldn't afford a 3-series" or anything like that.
Many people who don't know cars just assume its a 3-series until the look closely and like many of the commenst here they never heard of a 1-series. But they like it.
In the past week and older lady stopped in the middle of a busy parking lot to say "nice car" and some high school cheerleaders were having a car wash and told me "your car is too nice for *us* to wash!". So now my wife says my car appeals to high school girls and old ladies. Nice.
A high-level exec (who has lots of fancy cars including an M5) said he liked it and when I told him it had the same motor as the 335 he said it must be fast.
But all comments I've gotten so far have been positive, at least to my face.
2012 135 Convertible
2010 Lexus RX350