I have NO idea what system you guys are talking about....but it can be any different than a rattling bag, or the two grunt tubes that primos had that you rub together, or those set of square plastic sticks that are rectangled shaped that you can buy like a rattling bag.
Its all in what you believe in....If you believe a rattle bag will work and you use it enough...it will work eventually. If you only think real antlers will work...they will.
I like to envison rattling sequences in my head as I rattle, if I use a rattling bag I cant picture the bucks going head to head and I think it sounds bad so I usually go back to real antlers.
Its all in what you believe will work.