Here's a testimonial I came across online. I thought you might be intersted to hear what somebody else had to say about it. This guy has a modded Z06 Vette.
"The Star(SPEC) clutch needs to be broken in, and it's not fun. It's so grippy, I liken it to a light switch as it's either "on" or "off." So, you will either kill the engine, or it will chatter a bit for the first 200 miles. Then it gets a lot better. When it fumbles a little, it's usually my fault. After 1st gear it's no problem.....even when new. Down shifting, which I try not to do too much of on the street as it just wears out your clutch faster, requires faster clutch release and matching engine and clutch speeds. If you take your time and the engine slows down too much you will feel a little jerk when it grabs because of the speed mis-match.
This clutch hooks up like no other I've ever had. My buddy was watching me speed shifting and said the front end really jumps a good 6'....maybe a little more."