I had a homemade version of it on my Old Glory back in the late winter/early spring when it first started to become a hot item. It initially did seem to make an already quite bow even quieter. I did pick up 2 fps and accuracy seemed improved as well.

However, after shooting it for a month or two I opted to take it off just to see the difference again. I was more than surprised to see that I hardly noticed a difference at all. I have not had it back on since.