Personally, I love warm and natural (100% cotton). Many of the high loft battings have some polyester in them and I've found that you get some fibers working themselves through the top over time. Then they pill up..... I don't like that. Cotton batting doesn't seem to do that. And I like the flatter quilts (thinner batting).
I've never done a trapunto quilt top so perhaps someone else will have a better choice for that.