nah. never did. and if i did it reconned it to be some kind of exp-level-skillgain-stuff.
but nyah. flying choppers is kinda like in Battlefield (little harder but not much). Everything else is not comparable for me. I like the driving-system with the mouse btw.
For me its not been that difficult. I just had to put Crouch on C and LieDown on Left-Strg... double-C and double-Strg for standing up.
Whats annoying is the 2xW for sprint. happens to me all the time, couldnt eat as much as I want to puke... -.-
All in all: Just do the tutorial-missions a few times and you will be alright. ;)