I've had ARB air lockers for over 25 years in 2 vehicles, I tend to keep my trucks for a while....
Me, I'd go e-lockers should I change cars and find myself 'lockerless' not because I've ever had problems with the air lockers but the associated plumbing can be eliminated with e-lockers a lot less to go wrong with a wire than air hoses AND wires. As Winston says above.
That said my ARB's have never let me down and they are still one of, if not the strongest products on the market, axles will snap before the ARB lets go in 99.9999% of instances, seen it done on the axle dyno, and seeing as I used to work there in a previous life and was right into the sourcing of components for them, there's no cheapskate compents in there, believe me.
And I'll vouch for a rear locker only first over any rear LSD and front locker combo, having had both the practical experience over YEARS plus worked in the game for a period of time and heard all the stories. I've also seen brand new GU patrols spinning one rear wheel on grass on the flat with the other on gravel just trying to get moving in my own back year too, LSD's are not much use at transferring toques from one side to the other, Toyota LSD's are even more pathetic, lol.
My 2c based on industry and practical knowledge anyway :-)