well just took my hummer out today with both differentials locked and man is it unstoppable. only thign that stopped it was grass that got to thick for its low lift. i even drove it through a ditch with shallow water in it...water shallow but deep enough to come up to the bottom of the doors....splashed right through it. For those of you who are going to get a hummvee....lock the differentials, you wont beleive the huge amout of difference it makes when those differentials are locked. With locked differentials its even great on the pavement it has better power transfere to the wheels and better handling, so far i havent flipped it turning at full speed, When i drove it without locked differentials the other day it was liek driving a modded 2WD got stuck everywhere, but now it just plows through everything i drive it through.