I switched from a shakey hunter to the Drop Zone a few months ago. While the TT is a solid piece of equipment, it was a little too noisy for my likings. And I didn't feel like messing with all of the mole skin, etc.
The Drop Zone uses a cord that ties into the down bus cable. At full draw, it vertically lifts the rest into position. Upon release, a spring pushes it down out of the way. One word explains this rest: Awesome. It has worked flawlessly me and it is totally silent. I'm sure that is not the best description, so check it out here:
http://www.trophyridge.com/cat29_1.htm