Re: OX TRAX locker for Samurai?
I don't know about the quality, but I do know that the shifting mechanism is an integral part of the diff cover (i.e., you have to replace the stock diff cover with the Ox Locker diff cover, which contains the shifting fork). Since Samurais don't have a removable diff cover, they would have to come up with some other design. Also, I saw the electric solenoid locker, but it is basically the same concept as the cable-activated Ox Locker. Instead of a cable activating the shift fork in the diff cover, you have a solenoid that moves the shift fork.
I did see a selectable electric locker recently that had an internal locking mechanism (i.e., no shift fork needed). However, I think there were still wires that needed to be run to the diff. I can't recall the name of the locker though.