I've been using the Throttle Rocker on my '04 FJR for several years now and love it . I have no interest in having a throttle lock on the bike but the Throttle Rocker works great to rest my hand while riding. I have the version with the velcro and use it over Grip Puppies without any problem. The velcro can slip but I solved that problem by wrapping a 1/4 inch rubber band tightly over and around the rubber collar they provide with the Throttle Rocker, which allows the velcro fastener to grab securely and not move (one of those small, wide rubber bands the stores frequently use to bundle together broccoli, etc. etc. worked fine for this purpose). The Throttle Rocker could be dangerous in the twisties or in slow speed maneuvers if you aren't used to it--it's very sensitive to the slightest movement of the hand. I remove it if I allow someone else to ride my bike. Once you get used to it however, it's great, I've had no problems with it in the twisty tight stuff or slow speed maneuvers. I also use one on my Gixxer sportbike and love it.
Lee in the Mountains of Northern California