Ok i will go against the grain and say:
The only reason to get an ARB is you drive it a TON on the road or you like the sound of the compressor every time you flip the switch.
No offense to Kurt, Bart, or Carl (my friends with ARB tattoos)
Max Power; said:
They just need to be installed properly.
In another life I was at a crawling comp (yeah a million years ago) and watched Nick Campbell time out on an obstacle because his ARB had an air issue. You can't tell me it was installed wrong. It just happens too many variables.
So I guess my point is if you need the street manners and can put up with the possibility of not having a locker, (compressor issue, line issues, silinoid issue, fitting issue, seal issue, etc.) then get the ARB.
If you want a dependable locker with decent road manners think about a Detroit. Things like spools and Lincoln lockers don't count. Yeah they work but you'll probably hate them.
Two more side thoughts
1) for those whining about tire wear and such with a Detroit locker they havent figured out how to a) turn a hub out, b) shift out of front/4wheel drive, or c) coast through a turn.
2) while a lock rite acts similar to a Detroit don't pretend they are the same. It's like your yuppie friends telling you they go hardcore wheeling in their Subaru.
(Let me know if you don't know who Nick Campbell is)