And that helps everyone else how?
I have a nismo 2 way gt pro in my car atm. It does clunk, but remember if you push the clutch in it stops the clunking/squeeling and just free rolls like a std diff does.
It is one of the best mods i did to my car. Power gets down a lot better. It is more noticeable under accelleration through a corner, and makes the rear heaps more predictable when it decides to step out. It wont hurt driveshafts.
Only time its ever been scary was when i first got it and was geting used to it. You need to remeber the arse will step out if you have to do an emergency brake, but keep it in mind, and push the clutch in if you ever get into a situation where u have to brake hard (which you have to do if you're coming to a stop anyway) and you wont have any problems....