ARBs also have lots of issues with air leaks. Not just air leaks in the hoses leading from the air compressor to the differential but internally inside the locker. There's seal issues. That's one of the reasons why I shied away from going with ARB. Eaton e-lockers have a good reputation for reliability and it was recommended to me by my buddy Nick who owns Yota1 Performance.
As I've said in the past, having owned something like 8 ARBs over the last 25+ years....I'm not sure this is a fair characterization.
ARBs
can have air leaks....improper install is usually the culprit, though someone here a few years back said ARB was having specific issues with the Toyota seals. I haven't had a new ARB in a Toyota diff in more than a decade now.....mostly in D60 fronts now...no issues. I do find it a bit suspect that ONLY Toyota diffs would have the issue. ARB is still the comp standard....which is saying something more than simply sponsorship dollars.
Eatons had a fair amount of failures when they first came out with the e-lockers, but to my knowledge have shored up those issues (mostly the way the first design located the acutator in a vulnerable position).
The way to avoid issues with ARBs is to 1) install it correctly. 2) Don't use that crap blue line they supply with it for air (use SS braided teflon lined instead) and 3) use an air switch instead of the electric switches that come with it.
Not sure what the market is like for Toyota diffs...but Yukon's Zip models have competition models whose default position is locked.....though up front, without full hydro, spooled would be far less than ideal.
All that said, my latest builds are all auto lockers.....mostly the Grizzly. Simpler, more economical, no forgetting to turn it on, etc. If I was building a cone dodger, I'd be doing selectables f/r (along with 4 wheel steer and portals most likely).
For a 7.5" Toyota diff though...this is all largely academic.
