I'm running the act hdss on an act lightweight flywheel. Honestly the clutch feel hardly changed from stock, besides the position of engagement. Even though it's a heavy duty, it still feels like stock. Barely any more effort is needed to engage the clutch.
The lightweight flywheel is ok. Revs come sooner, but also drop really fast. I noticed I have to Rev about 1k more rpm than from stock for the engagement to be as smooth as stock.
Otherwise, they pair together really nicely when the revs are high, clutch is released, and shit hits the fan.