IF,your follow through is good they work incredibly well. If, like me you have a tendency to relax your bow arm at release, (workin' on that Boss), you'll find that you're shooting about a foot to the right. You'll gain a few inches, say about 3-4 of draw length without fighting your body's natural range of motion. The release seems smoother to me. Read "Kay's Thumb Ring Book". I find the ring from Three Rivers to be most comfortable for me, fit is important, poor fit will reward you with a really sore thumb. Trim your thumb nail way back to start.
Z