Good point by Chuckman - I've got barely enough power to accelerate downhill, ~105-110" WB, and easily weigh north of 4k lb. Different animal for sure.
I don't think you can go wrong with an ARB if it's set up correctly. I like the OX, and the fact that I don't have to worry about a compressor or lines, although honestly it would not be a big issue. I'd be happy with either. The biggest PITA with the OX I've had is getting the diff cover on without smearing all my RTV off. The shift fork is built into the cover, and I was doing this laying under the rig, but hopefully it's not something that needs to be done often.
