I bought a Bear TRX when the SHOCK STOP system was first being used. I loved it and thought it was an excellent idea and worked very well. They just couldn't get the material down right though. I broke like 3 of them before I just gave up on it.

I have been debating an STS system for awhile but the string wear at the contact point doesn't thrill me and I hear people say the bow makes a "smacking" sound when it slaps the STS stopper.