This is my first BMW, but I test drove both the 35i and the 50i. Price was not really much of an issue, so take it for what it's worth..

The 50i is a BLAST to drive. It will kick you in the pants every time you touch the accelerator, no doubt. I shouldn't say this - I'm sure I'll get razzed on it - but that wasn't always a good thing.

Both passengers on the test drive (friends of mine in the backseat) were literally nauseous the whole time. The vehicle had, for better or for worse, a tendency to literally JUMP off the line and while this is really VERY exciting, in daily use, it would probably also be VERY annoying. There's also the fact that it gets like 14MPG.

The entire time, the SALES GUY kept telling me that the 35i was probably plenty of power, not to mention its significantly better fuel economy. After driving THAT one, I tended to agree. Aside from sheer acceleration - which, in my humble opinion, is PERFECTLY adequate on the 35i, there is no difference in the experience. From what I could tell, they are identical in every other way. Salesman pointed out they have slightly different rear ends, but at a glance, you would never know.

When I expressed concern about acceleration, that's when he introduced me to SPORT mode, and while it's not the same as that beast of an engine, it's good enough.

I went with the 35i, of course, and have not regretted it.

This is my first performance vehicle, however, and I may well change my tune in a few years when its time for a new one and maybe go with a bigger engine. For now, though, the 35i is plenty, and I appreciate the improved fuel economy (and the range that goes with it).

Try one - the turbo and this eight speed transmission makes a big difference. It seems to stick a little between first and second, but so far I chalk that up to me not being used to a vehicle that wants to get up and go in the first place.