I have not personally used QD, but I can tell you that Naps is a top quality source that has been doing this for a long time and would not risk ruining their rep by carrying junk. I have heard lots of good feedback about Primo in general. Companies like QD have access to high quality raw materials. Its the small UGLs that guys are making in their basement, that you have to worry about. I imagine that most of those guys dont have access to the same high quality as the big companies do.