I'm 6'4", 250lbs, and I fit like a champ in my E34... I feel like a king on my throne! (My fit in the E30 is a whole other story.) The one thing I don't like about my fit is that the steering wheel is quite large... when I'm cruising on the highway and I want to rest my left leg, there is not a lot of room to fit my leg between the door and the steering wheel. However, as far as being able to stretch my legs out straight, it's beautiful! I've put a MOMO steering wheel with a smaller diameter on my E30 just so I can get into it without banging my knee, and I suppose you could do the same with the E34, exept that you'd be doing away with the airbag.
Over all, I'm happy with the way I fit in the E34.