my cousin has an OX in his jeep, and he likes it. hasn't really had any problems at all, with exception of occasionly needing to rock the jeep a little to get it to engage, but when he locks it, its solid.
I've thought about getting an ox for my truck, but since I want to drop a D60 up front, have been holding off on one until I decide for sure... ( no real reason to upgrade the hell out of an axle I'm going to sell)
-Rich