Im one of the few that clicked 330i on the vote, I find anything with an ///M badge = ///MONEY PIT!!! Parts are 10 times the price compared to non ///M parts and these older ///M's require alot more parts replacement as the years wear on. Forget trying to find good 2nd hand M spares too...Hens teeth!!
This is the reason why I won't own a ///M badged car. I had the same option and took the 330i, I and my wallet have never regretted that decision to this day. I like to call the 330i the poor man's M3 as it has close to the same performance yet cheap on the pocket. My gf drives the 330i from Brackenhurst to bedfordview and back each day in peak hour traffic on the N3, she gets 9.4lt/100km, M3 will never get figures like that.
Did I mention the 330i is a much lower risk on the hi-jacking list? You cannot drive your M3 or 325is around the block without someone trying to hi-jack you!!