I made several quilts this year with fleece backing. I really love the fleece on the back. I will tell you that as I was binding them I wondered if I should have used some low loft batting. The reason why I wish I would have put batting in is partially due to the pattern on the fleece. I have a fleece that has a white background and. In that white area I can see the quilt top showing through... and that bothers me a bit. Now I don't know if anyone else will even notice, but I do. As far as the weight of the quilt, I think it depends on what the rest of the quilt is. I have some quilt tops that are tshirts and jeans and I think those quilts are heavy enough without the batting. The others are all tshirt quilt tops adding the batting would have been fine. (Some tshirts are heavier than other tshirts)