I think the rpg is the best grip I've ever used(only ever used the durlin grip, not the aluminum one). I don't know if the durlin material is what does it, but the cartridges are extremely easy to attach and remove. even the spirit sticks a lil, and the t-techs stick more than all the others ive tried. still want to give Franco's a go, the look real nice, look like they would function close to the rpg. in any event Gaston made one hell of a grip!