Can't really tell the difference in my Viggen. Revs in neutral about the same, if not a *tad* quicker. Still un-revs at the same speed (visually via tach). Got the OEM flyweel back from the shop, and the weight of the OEM unit is ridiculously heavy - so the lightened one must be doing something right. Good to know that this flywheel is better built and is purposefully crafted, but I regret that I can't jump up and down and recommend it at this time. Probably a good baseline prep for future heavy-duty upgrades, though. Got the SPEC clutch, too - not any grabbier than OEM. Was expecting lots of chatter and stalling at launches, but turned out to be an ever so "slight" upgrade from OEM.
Rating: [3 of 5 Stars!]