I am a longarm quilter and use several different batts. I do like polyester batt especially if I have a quilt that some blocks have some fullness in them. Personally, I am not fond of Warm & Natural because it is too flat. If I want a cotton batt, I prefer Hobbs Heirloom 80/20 blend. I also like using Bamboo instead of W&N, nice loft, good stitch definition and doesn't shrink as bad as W&N.
If using poly batt, I do suggest NOT buying packaged batts. You cannot see how well it is bonded. My poly batting is dense and looks like a blanket. I can quilt loose or dense and still have softness.