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.