I've tried Aurifil and absolutely LOVE it! Slowly but surely I'm going to replace my colors with Aurifil. Once at a retreat we took the prices of most of the different threads and compared the yardage to the cost. If I remember correctly you would have to spend around $25 to get as much Coats & Clark as you can get for $11 in Aurifil. Per yard it was cheaper than any we compared it to. A spool seems to last forever and because it's made with longer fibers than most thread it is smoother and can be made a little bit thinner. By being thinner you can really get a lot on a bobbin. A full/queen size usually only takes about 1 1/2 - 2 bobbins depending on how much quilting you do.