Thought I'd chime in, and just discuss personal preferences and/or project needs a bit. Generally I prefer a puffier poly batting with less quilting than the current trend of densely quilted W&N (warm & natural/bright). Plus that feels very heavy and weighty to me. There are other times, however, when that is exactly the look/feel I'm wanting (that is, dense quilting or I want the weight). And then there are times when I want something very thin -- maybe even just a layer of flannel, I'm finding that when using things like fleece that I still like just a bit of something for the stitches to bite into. Typically when I make a crib quilt it is about half the loft of what I use for queen sized projects.
Most of what I do is "use" quilts, and most of those are donations. I'm not doing a lot of fancy stuff, mostly simple meanders or grids and now have a machine that has an automated serpentine stitch and will be using that a lot. Also, as someone who has allergies I'm trying to make things that will last while being washed often.
When I had access to my friend's long arm we had rolls of both W&N and a poly batting, I've used both. They both have their uses, as do specialty batts.