Remember that lower mass means less inertia. So you can spin the flywheel more quickly, but it will also slow down more quickly when you remove throttle and carry less energy when you go uphill. This won't matter on your track/weekend car, but bear this in mind if it's your daily driver.

i put the fi knock off in my car .it feels fine, didnt beat it down thoe.its pretty tight.i know a kid with a celic all trac who fed it up when installing it and they sent a new one for free.then got many awd drops out of it and it still works.but you never know in a month i might be saying im taking my tranny down.

and heavier flywheels help stickshift n00bs drive stick easier.

I have a Fidanza 8lb and loved it when I was n/a. I wonder if eventually I should upgrade but I think it's ok for now.

fidanza works fine for me