Ive had both now.
E92 335d re-mapped to a E46 M3.
Erm, mine wasn't a straight change, its been nearly 2 years between the two cars,
Out and out performance, the 335d is actually quicker, (re-mapped) and on the road would take a good driver in the M3 to keep up. Track day, the M3 is quicker... Just a sharper tool.
As long as you get a decent spec one you won't be missing out on toys, and the leather is of better quality than the dakota shit you get in the E92's.
The economy, I have found is better for me in the M3, I'm averaging 20mpg vs the 335d's 18mpg but not bothered about fuel costs.
I have achieved 36mpg in the M3.
I am going to the Pod and see how close I can get to the 335d time.
The M3 needs to be worked to be quick, but is fun and sounds glorious.
The 335d has that awesome bottom end shove of course, but you won't be dissapointed going to the older shape E46 in all honesty.
The 335d is the more modern car without a doubt, the fact your considering the M3 means you sort of know what your getting yourself in for.
Last edited by dxb335d; 04-12-2012 at 03:19 PM.