Been working with my mouth calls for awhile now. I definitely have a preference for Quaker Boy over Primos. Sound quality is nearly identical as far as I can tell. But the frames in the Quaker Boys are thicker, and the body material is significantly more flexible than the Primos. The Quaker Boys seal much easier on the palate than the Primos and don't rotate on me. This is the first year I've tried Quaker Boy mouth calls and so far I can use them better than any other brand I've tried.