I have been checking out diff locks for a while now and I would settle on the LOKKA from 4WD Systems but for one thing: It can not be turned off manually.
I understand in 2WD with hubs unlocked the diff lock has no affect on the front wheels so the patrol should drive like a stock truck.
In offroad situations the diff lock will always be on unless the auto disengage is triggered by turning on a hard surface.
So getting to the point...
Lets say your gunning it along in some soft sand and the lokka is engaged, all is good. Then there is a big stump on one side of the track and you have to put a wheel on it, I imagine with an ARB locker you would turn the locker off just before you hit the stump to avoid excess strain on that CV as the tyre hooks into the rock. But with the lokka you can not manually turn it off.
In this situation does the Lokka disengage and allow differentiation or does it stay locked and you have to hope for the best with CVs?