i would tend to shy away from the metal loops, i shoot with one and i liked it, but then i took it off and my bow, mysteriouly got much quieter. and also with that extra mass in the center of the string it will slow your string speed down as well as your fps, whether or not it is very noticable i dont know... if u want to try a metal loop i still have my old one. pm me if u are wantin to try it