i had a new 2010 MB E350 that i was not happy with. first year models always have problems, and my MB was not living up to expectations, so it went away.
i looked heavily at getting an F10 a couple months ago--great car. but, having come off a first model with problems, i decided that i didn't want to jump back in. i think the 2012 models should have the kinks ironed out. first year roll out betas are just turning out to be too much of a headache IMO.
Auf Wiedersehen 12 550xi