Anyone else favor these? I switched from the glutes on the latest pin and I liked the control aspect and all, I was wondering though.. half my quad is pretty sore... is this just from the reaction of the new muscle from a foreign substance? I know I got it in the muscle, it was quite a distinguishing difference when I inserted the pin. Im just wondering why the injection site isn't sore but a lot of the muscle itself is... any takers? thanks