I think what the E46 gains in power over the E36...it gives back in weight. But the S54 is more reliable. Can you say oil pump nut?
But the E9X is a beast. Bone stock, I think it would be better for auto-x since it rotates with throttle much better than the E46. In the E90 just pin the throttle to the floor with a little steering input...you'll be facing where you just came from in a split second.
2013 F30 328i Melbourne Red
2011 E90 M3 Monte Carlo Blue
2004 E46 M3 Imola Red