Re the lady who is saying it comes apart, chances are she has quilted it further apart than is appropriate for poly. As you mentioned, the poly has given you a recommended distance.
IMHO if your friends want puffy, poly is the way to go! Take a look at the thread I just started ... poly batting was used, and the quilting does show puffy, but not overpowering.
http://www.quiltingboard.com/t-136789-1.htm
There's a lot of other batting possibilities than cotton or poly, so I'll look to hear what others suggest.