i've got the obx lsd in my car. I just recently put an sr in the car and havent taken it to the auto-x yet but it does its job just fine. I followed Aceinthehole's example and opened it up and found that atleast one of the belleville springs was cracked, but i was planning on replacing the stack with a new set that was more beefy than the one that came with it. Other than that they are bulletproof; nothing can really wearout on them.
here's the thread that has alot of aceinthehole's info
http://zilvia.net/f/chat/101109-obx-...ng-review.html
and if you need i can dig up the old part numbers of the 2 sets springs i purchased.