I have used the Gutterman with no problems. I like Mettler 60wt, and Superior Master Piece for piecing because they are thin and strong. For quilting, I like Mettler 50 or 40wt (linty, though), Superior King Tut, Star, Sulky 50wt, and a few others. I have made two quilts with Aurifil and both have popped quilting lines. Not happy with that.