I installed a Phantom Grip about 6-8months ago???
No problems with the diff, but it's not a replacement for a LSD. Since it's a friction type Lsd I think it wears out... it doesn't hook-up the same way it used to when it was newly installed.
FYI I've heard that the Quaife goes open when one wheel is allowed to spin free (like if it leaves the ground or even when wet) and is the reason rally cars use clutch type LSDs. I'm not sure if that's even a bad thing, really.
I'm waiting/wanting a Nissan clutch-type diff. (Please Lord send one my way, or let me win the lottery) As far as price, aren't Quaifes around $600? If you can get a Nissan LSD for $750 that's where I'm gonna put my money.
My 2 cents bros.
Jon