I have both cars too.... the M for 18 months and the 135i for 12 months. Anyways, the 1 is the shopping car with kick and no noise, the M is what it is.... a sometimes sedate limo then a screaming monster with alot of street cred.
Comparisons, build/equipment?? well you get what you pay, Nappa/Individual Audio, auto everything and they are all standard. Where as in the 1 well start ticking the boxes (+++$). Suspension, - no comparisoms.
I am looking now for a replacement car... which one is going? the 1!
I guess I may look at this a little different than others, I have wanted an M since the E30 so it ain't goin nowhere. The 1 on the other hand will probably make way for a TTS/MkVI GTI/R20 (golf).