Junk..well, that is one mans' opinion.
I have a lock right in my 9 1/4 on my big truck. I have had it for about 8-10 yrs now, running 350 HP, 4.56 gears, and 38-39" tires (they recommend 35" or less). I have been thru 2 housings now with it, and it was NOT the cause of the damage...my heavy foot and too good a traction was (I split the housing wide open on both axle tubes), lots of serious wheeling, and it still works great. I have seen no signs of any appreciable wear on it in the 8-10 yrs it has been in, nor have I had any problems with wear particles from anything in the rear (except the occasional water that creeps in when you do lots of playing in deep water & mud). I have had many on here say it is junk, but from my experiences, it is a reliable piece of equipment. If I had another truck to build with a 9 1/4, I would use it again with out hesitation. I do know that if it is not set up correctly, it will give you lots of problems with wear and play.
I would prefer an ARB, but they don't make them for the 9 1/4.