Did you know that all the newer sewing machines are pre-set for Polyester thread? This is the tension on your machines, and that is an important thing.
I was told yesterday that it is okay to use Polyester thread for your quilts. If you use cotton thread it makes more lint in your sewing machine and you have to keep it clean around to bobbins area because of that. This info was given to me by a teacher that has been quilting for 37 years and I would said that she knows what she is talking about. She also works in a high end quilt shop, and goes to all of the Quilt shows and talks with the people who make the sewing machines.
The older machines that are not as fancy as the newer ones are not set the same. But one note I will say I notice how much lint builds up and I quick that happens.