Years ago I tested a all aluminum BHJ balancer on a NHRA class leagl 340 stocker motor versus the stock balancer,13 lbs versus 7 lbs, no stinking changes on torque or horespower none at all measured Looking back now we should have done that test at the track, not on a engine dyno As far as which one is better at absorbing crankshaft shocks I bet the heavier one is better, maybe not I have both types of ATI dampeners on my motors, I can't tell the differences between them. The motors are not twins so not a decent comparision at all