Originally Posted by
terraphantm
Secondly, M3s generally have quite a bit more bracing than non-Ms. So even if the 330i is stiffer than a 330ci, it is probably not any stiffer than the M3.
3rd, the handling of the 330 doesn't hold a candle to the M3. Both are very stout cars, but the M3 is just another level. The suspension geometry plays a very large role in that.
Having driven both cars extensively, I would say the M3 is simply a better car. Ride harshness is about the same (assuming non-blown shocks and same tires on both cars). The only thing that might make the M3 a bit of a chore in some peoples' eyes is that the controls are generally a lot stiffer. Stiffer brake pedal, stiffer clutch, stiffer shifter, stiffer steering. But if you don't mind that (or even prefer it), the 330 has no advantages.