I'm curious on average how long clutches generally last for..?

I'm going to be building up another block and am trying to decide on what clutch to get. I've been running an ACT clutch w/ the Xtreme PP and the street disc and I can say that it really is a wonderful clutch for the street. I haven't run the car at the track w/ slicks, which I'm worried would wear out the disc alot faster.

I'm just curious if it's worth buying a new pp and disc, or just buying a disc to replace the full face..? I've been running this clutch for probably a good 30k miles, so I'm a bit concerned that it might be ready for a replacement. I've been running around ~300whp for a while, and it holds it w/o a problem. I was pushing higher boost for several months daily, probably ~350whp, and it held it w/o problems as well. I'm wondering if I should just purchase another xtreme pp, and something like a sprung 4 puck disc, or just buy a new disc and rock the pp i'm running now..? I'll be able to make a better judgement when I pull the motor and take a look at the clutch, but I'm curious generally how long they last.

My other issue is that I'm looking to push a solid ~350whp on the street, and 400+ w/ race gas. The car is not daily driven, but I do like driving the car a few times a week. The stiff pedal of the xtreme pp doesn't bother me at all, but the price/noise/longevity of twin disc setups aren't really that appealing. Anyone have a good recommendation for a solid clutch setup that can handle a good 450whp besides a twin disc setup? I know that's definetly pushing it, but I'm not sure what's out there. Thanks.

-Mike