Depending on the quilt is how I decide if I want flat or puffy. The quilt I am working right now I want a bit of puffy. It is a baby's quilt and so a little puffy is desirable. Wall hanging I want very flat so pre-wash and shrink as much as possible and then quilt closely. The quilts currently on my bed are very flat. Pre-wash W&N batting quilted closely. The primary one in my guest room is a bit more puffy. It has a poly bat still quilted very closely but has a bit of 'puff' to it. Now I have a hand quilted quilt with a poly bat that has a bit more puffiness to it as it is not quilted as tightly as some of the machine quilted ones. So what I am getting at is that it is all up to what you want as the final outcome of your quilt. I think of all these things too when I am making a quilt.