YMMV on a 330i, but they perform great on my car. Doesn't affect ride at all (sways shouldn't, really), and does a great job at quelling body roll. They are noticeably thicker than the stocks (I have SP), and they probably need to be to show that much difference. I originally ran the middle position all the way around but was getting too much understeer, so I adjusted the rears, and it's much better. Also, before I put them in, the tires (PZero Rossos) had awfully poor lateral grip, but work way better afterwards. Not sure why this is the case, (change in contact patch or weight loading, probably) but it was just as noticeable as the change in body roll.