You really can'tadjust it on the fly, unless they have radically redesigned it since I had one. I need one that you can adjust while riding- setting it for the most comfortable position for whatever speed I am going at the moment. I use the throttle rocker every now and then, but prefer a throttle lock device that holds the throttle without any hand contact. I prefer a removable one too, as the throttle rocker or boss can really be in the way if you aggressively countersteer to carve up corners like I do. But everyone has their own taste, and everyone has their own riding style. I think he has the right idea- try the concept with the cheep one, and if he finds he likes it and does not adjust its location on the grips much, then buy the more expensive and permanent one.