Had E92 335i 6-speed with sport pack, now have M235i 6-speed with M-LSD
M235i feels more solid, more reliable, more fun to drive, 6-speed tranny feels much better. But that said E92 didnt feel special and got boring after 1 year, M235i doesnt feel that special either, but not bored yet cause like I said, its more fun and a better car in general.
E92 had some issues including major issues with turbos, so far M235i is rock solid but I only have 20k miles
(knock on wood)