I've got the first he ever lightened and I like it. Since i have a VE that has a 4CW crank it spins up faster.
Its not as lightened as the one seen in the link he provided but would be perfect for a P11.
I just happened to have the clutch disc come apart so i had a chance to take pictures of it installed after some use (including a track day at AMP SR2013 Convention).. I'd say the quality is better since its a factory part (and you can't beat factory) and its lighter than factory so definitely can't beat it. Had I known he could of done one like that when I got mine I would of waited.
This one ^^^^ is about 14.25lbs if I remember right.
I don't really know what you mean by how fast it is. Lighter flywheels don't give you any more horsepower, but do allow faster acceleration due to reduced rotational mass. The end result is similar to taking weight off the car. Well, yeah, I guess you could say it's faster. lol
This is very close to 33% lighter than stock, with almost all the weight off the outer edges where it makes the biggest difference, so it should make a hell of a difference as far as flywheels go. But then compare it to the price of a Fidanza.
If you want to run it without surfacing it I can drop the price a bit too.
Well, it's in between the stock weight and the real light flywheels Fidanza offers, I would say yes. For a daily car that isn't a serious race car a real light flywheel can be a bit of hassle to some people. The little bit extra care taken when engaging the clutch from a stop is fact, but it's a small difference you get used to pretty quick. For many it isn't a problem, but going to an medium weight flywheel would kinda be the best compromise I think. Mine is good for only factory rpm limit so a engine built for fun and not a full on race set up would make real good use of it.