I agree, I've done some of the hardest rated trails in Moab without a locker. Moab rim, potato salad hill, poison spider mesa-golden spike- gold bar rim, ect... all with open front and rear. A lot of it in 2lo too ( t-case started slipping on the first trail of the trip).
That being said, we just bought our 01 with ARB front and rear and the difference is incredible. Especially in snow and slippery stuff.