[BavarianBullet]

I went from an 08 335xi to an 11 335xi:

Auto works well for the most part but with the N55 it revs way too high and the manual shifting is way to slow under WOT. Good for drag racing cuz you can brake boost. With big mods (well over 400WHP) the trans won't last forever and so far no great trans upgrades, depending on who you ask.

The 6MT in my 08 irritated the crap out of me for the following reasons:
1) Second gear hard shift problem: This seems hit or miss in that it affects some cars but not others. It happened on my 08 and my friend's 08 but not another 335i that I drove. If you have it, you're screwed and won't really be able to quickshift into 2nd under WOT. It'll just grind. No fix AFAIK.
2) Reverse is next to 1-2, so when trying to quickly throw it into first it will sometimes land you in reverse
3) Stupid clutch delay valve. Just remove it and optionally replace with drilled one for $20. Goes from granny mode to normal MT car. Removing the CDV will make the trans whine slightly if you beat on it and trans loosens up a bit (that's what the CDV valve is there to prevent btw).
4) shifter is tall and shifting it hard will rip the shifter knob off (!). Only good mod I did was the UUC shifter for nearly $350. Stupid shifter knob isn't threaded and can still pop off though.

FWIW, I'd buy a 6MT car if the 1-2 upshift under WOT problem wasn't present. I could live with the other issues. 8AT in the F30 is niiiice though. Shifts way faster than the 6AT.