I use fleece a lot... I think! We call it polar fleece, and it's kind of fluffy, and stretches?
It's great on kids quilts, cuddly and warm. I don't generally use batting as well, although I have done on one that was for a small child with cancer, she needed to be kept warm so put the batting in for extra thickness.
I've never had any trouble with it going hard through stitching, or stretching.