Like you, I find myself making a baby quilt every month of two. I used Hobbs 80/20 batting when my quilt backings were 100% cotton. Now that I'm using Minky as the backing fabric, I don't use any batting at all. (My quit tops are still 100% cotton.) So far, the young moms seem to prefer the Minky.
As you may know, current advice from the American Academy of Pediatrics is that NOTHING be in the crib other than the baby and a crib sheet. As a result, I don't worry about the baby becoming overheated - cuz s/he is never under the quilt. The Minky is also lightweight, so when the day comes that the baby might want to drag the quilt along with him/her, it's easy.
My newest concern is that the Minky is so strong that my pieced cotton side will wear out too soon! (My pieced side is an I-Spy with 80 different squares.)