I love their Poly for piecing and quilting on my Janome 6600. I've used Poly and the Cotton Cones successfully on my Gammill Charm, not noticing any difference from the other, more expensive brands. I will say that I wasn't very successful using the small cotton spools on the gammill. It may have been user error, I haven't had a chance to try again, but would like to figure it out, as I have 40 colors in the cotton spools.