Originally Posted by dxb335d
The diff alone is worth it for me. Makes the standard diff in the 335's feel pony.
335i does not have a diff at all. BMW calls a variant of their DSC "electronic diff" but that is a complete misnomer.
I've driven both cars quite a bit and agree it depends on your priorities and your financial situation. The 335i is a better allrounder and more comfortable in daily driving, the E46M has far better throttle response and a better suspension setup if you push it a bit harder. To get the 335i to the same handling point or better you need to spend a bit of money, with the E46M that's already included as standard. But then, the standard suspension of the 335i is really not that bad, especially if you ditch the RFT tires.
Then again if you like loads of torque and mainly drive on motorways, the 335i - in particular if chipped - is probably more adequate.