I had Potenzas on my M3.....don't remember the model though. The main problem for me is that I live on a hill. Any time it snowed I just couldn't make it up my street to go anywhere. My roommate had a 330i with all season tires and had the same problem. Yesterday the 335 didn't even struggle at all.
Seems like DSC vs. DTC is a matter of preference depending on your driving style. I tend to be a little more cautious in the snow. Mainly because I don't trust anyone else out on the snow. I guess time will tell which I prefer.