I cannot tell you what the Phantom grip is made of but I did have one installed in an 016-5N. I used the unit because the price was a lot less than what a torson unit ran and I felt it would meet my requirements for most conditions. It did what it was advertised to do and I was happy with that.
I realize that you can find better units at around $1,500 bucks but does it make sense to have a LSD that cost 5 times what you paid for the transmission? If i was running a Porsche or other expensive box I would have chosen a different unit.
Peter