MQ1, of course with my Legacy, it has the built in string dampners at each end or it already, and I never added any string leaches to it since I bought it, BUT the STS definately made a difference in how it feels after the shot and how quite it is. It is just a THUMP so to speak, no twang at all.
When I first gotthe STSand installed it, I just didn't like how it looked, so with in an hour, I had it modified and mounted, and I won't be taking it off. I never chrono'd mine before and after, but I have heard of guys getting upto 3fps gain with the STS, and I have never read any where that anyone lost any fps!
I have mine just a hair from touching the string and I also served my string at the impact point, although it wasn't called for!