sweatshirt fleece works well too (sweatshirt jackets are proof of this!)
i don't think the stretch is any more than any other fleece, it all stretches so you have to be careful to lay everything out nice and smooth without stretching it. other than that it quilts up easily, the stitches sink into the fleece and really don't show much. once you make one...everyone is going to be asking for them :)
everyone i made quilts for in the past (with regular cotton backs) wants a new quilt with fleece or minkee on the back!