Hmmm, the OP did not really cite details as to why. Normally I'd expect someone to cite what the don't like about the E90 and why they are attracted to the E46.
Possibly feels to me like the OP has a changing financial situation which could be forcing his hand.
Hey...not taking shots.....was in the same shoes earlier this year. Newborn son caused me to part with my 135 and the monthly payments and bought in cash a nice '02 M3 as a replacement. Very happy with the swap.