For me it depends on how I want the quilt to look when it's finished and washed. If it's an old fashion style quilt I'll use a new Hobbs Heirloom 80/20. If it's a really modern quilt that I don't want to get puckered I'll shrink a Hobbs or use Quilter's Dream poly. It's the only poly batt I'll use. The Hobbs has a bit more loft and gives the quilting a little more definition and the QD poly is really flat.
I don't care for Warm and Natural. I used it in a couple of the first quilts I made and it was very stiff. Those quilts were like boards when I got them finished.