Between our 3 Jeeps I've run an OX, a "full" Detroit, and an ARB. ARB is and would be my first choice for a locker were I building another axle. My XJ has a Detroit in the back and while it's not bad on the road, it's annoying in a daily driver that sees commuting traffic. The internal backlash coupled with lower gearing (4.56s) creates a bit of a "kick" as the driveline transitions between coast and power as you get on and off the gas. If I blip the gas just right while coasting you'd think we got bumped from behind by another car. It'll also roll a couple of inches in Park if I don't set the e-brake (auto trans). Offroad it's excellent though, but I'd never use a Detroit again personally for a daily driver. After my experiences with a Detroit in the back of my XJ, I put an ARB in the back of our TJ.
We had an OX in the front of our TJ and honestly can't understand how people can screw up the cable install. Unless you route it wrong and melt the cable, it's all spring loaded now so there's really not that
much adjustment that has to be done to get it to work properly. Bonus with the OX is the heavy-duty cover you get, and shifters are cooler than switches.
Cable routing and shifter location can be troublesome though, and we have had our fair share of OX troubles (though they were ALL related to 1st gen design flaws which have since been corrected and OX was always great to deal with).
Like I said at the start though, my choice would be ARB. Got one in the front of the XJ and put one in the back of the TJ, and if we hadn't gotten a Rubicon JK, it'd be rockin' a pair of ARBs. As far as ARB vs OX goes, for me a lot really just boiled down to air line is easier to route than cable, and switches are easier to find a place for than the shifters. The all-mechanical action of the OX definitely wins in the KISS department though.
I'll echo the others' sentiments on the durability of the D30 though. Both our XJ and TJ have D30s (low pinion at that!), are locked, with low gearing, and 35" tires (and some 36" beadlocked IROKs for a while) and have never let us down.