I have these in both diffs. Granted, i DO NOT see rocks very often. I use my lockers very sparingly when going up (or down) loose packed hills in trails. It does not rely on the clutches to lock it. it uses an electromagnet to pull a cone/bearing setup together to spool it. The clutches only see real use when open, due to it being a lsd when off. I guess it is not as reliable as a good old detroit for crawling, but there are some good advantages
1. For those of us who want a selectable locker, daily drivers who see wheelin every so often(jeeps are great because they are just as fun to cruise in, top down, lookin down at super dutys!)
2. they are a selectable locker at 550$!!!!!!! not 700-900 + cables or stupid useless compressors that die if u use them for tools or airing up/down
3. the lsds really are nice in winter, rain. No more fishtailing on acceleration at lights
4. Believe it or not, there are those of us who do all their wheeling on our dana 35's (i have 33's and dont want/need bigger tires) I do not think they make an E-locker for the 35(I MAY be wrong, but I looked first) My super35 kit in my yj lasted 3 years, and i like the skinny pedal(in my 4cyl) No probs.
NOW...I admit I only have had them a couple months, and they have seen limited use. we shall see what time will tell, but for now i love them. I think they are good option for those of us running smaller setups who do minor wheeling. If I had moab type places to wheel(I'm in CT) I would probably have a D60 with 513s and ox lockers or arb, running on 35's or bigger, but my 2.5 tj with 488s on 33's is a perfectly capable weekend wheeler. Plus it is just fun to drive!!
Just my honest opinion, from someone who owns the product.
97 tj, 33's and a 4 inch lift, locked front and back, 4 banger and proud of it!
Low Output 4 Cylinder Jeep Club Member # 42