I think, if the bow wasn’t already so quiet and still they would make a difference. I know a couple of people who have them on other bows and they made a real difference. I didn’t leave them on long enough to run the bow past a chrono. They may have increased arrow speed a couple of ft/sec, but that’s not enough to make up for the added weight and no other benefit.
I had what i thought was a super quiet xtreme,deer never knew what was going on,not one evewr heard the bow go off.I then added monkey tails to the cables,and cat whiskers to the string.Once i did that,tghe bow was really quiet,then another buddy showed me BOWJAX,I added a set to the limbs and holy crap,I never would believe it ifi never actually did this stuff myself.I have the quietest bow i’ve never heard LOL