They have some local MX guys reporting a significant decrease in arm pump and heart rate when using these. The V-twin road guys seem to love them. I have two dual-sport thumpers that OBVIOUSLY benefit from vibration dampening, but, I thought my inline four CB felt fairly smooth. So, I was wondering what I was doing wrong when my hands would start to get numb on the CB. They put these in my bars, and BAM! Dead quiet. No more vibration, no more numb hands. (Actually, I do recall there is some vibration at around 2500 rpms...I'll have to go pay attention to be accurate...but, I never ride at 2500 rpms, so, it doesn't matter to me.)
Anyway, it's technology that actually comes from helicopter vibration dampening. The tonic muscle reflex contraction stemming from vibration is an interesting topic that's fun to explore, in case anyone is interested.