bad idea to poll a comparison of an m3 e46 on an e46 forum???
as you are from the USA (mostly straight roads), the 335 would be better for you. I have an M5 and a M3 e46, i love the handling of the e46 but do miss the torque and in gear pull a torqy engine like the 335 & M5 would give you. With all those straight roads a 335 would be lovely, although i would miss the LSD......
But still a 335 in the US and a e46 M3 if living in the UK, does that help