Good article on Marc Haibeck's website.
http://www.zr1specialist.com/HAT%20W...el-clutch.html
Marc believes the PP is good for 550chp. I have had good reliable experience w my setup which approaches that level of power.
With the Fidanza you'll want ARP bolts that are the correct length. I believe both Marc and Jerry's Gaskets have them.
With judicious tuning, and good trans lubricant the idle rattle is minimized at idle. There is no rattle once clutch is engaged. I just switched to Amsoil Manual Trans fluid since the Castrol is no longer available through BMW centers.
So far I have found the Amsoil to work just fine maybe even a bit better than the Castrol in controlling idle rattle with higher fluid temps. Shifting smoothness hasn't noticeably changed. I have a Hurst short throw.