I have the Mantic 9000 twin disk clutch and like you I was pleasantly surprised at how much easier a twin is to use than the stock clutch. I was thinking because it had 2 disks instead of one that it was going to take more pedal effort but it was just the opposite. I'm not running the high hp you are so I didn't go with the ceramic facing, I chose the organic but the improvement in clutch feel was amazing. It's smooth, clean, precise and very linear; no sudden grabbing. I just crossed the 500 mile break-in point on mine but so far I'm very happy with it.
If anyone is hesitating getting a twin because they think it's going to be harder to drive don't give it a second thought; they're great! Here's some pictures of mine on my project thread in case anyone wants to see how a twin looks compared to the stock clutch:
http://www.camaro5.com/forums/showth...=45165&page=10
I chose the Mantic because of the weight savings but I've heard nothing but good about McLeod.