Do you hand quilt or machine quilt?
I machine quilt on a longarm. I like Polydown. It gives great definition to the quilting. It is very cost effective. But I don't think it has very nice drape. My favorite cuddle quilt has W&N in it and was simply quilted with a 2" cross hatch grid on my domestic. So maybe the combination of cotton batting, the fact this quilt is older and has seen many washings and the fairly sparse quilting is what makes it such a wonderfully scrunchy nap quilt.
Cons of polydown are
It is a synthetic and a lot of people don't like that
it can be slippery so if you quilt on a domestic you have to make sure you baste really well as it can slip around some (I don't know if it can be spray basted, I assume it can)
Until the quilt is fairly well "broken in" the drape is not very supple.
Pros
It is extremely cost effective
It gives great definition to the quilting
It is comfortable to sleep under (at least in my experience)
Edited to add it is extremely easy to launder as the batting is light weight and dries really fast.
Also it makes for a much lighter weight quilt than cotton or 80/20 which could be a pro to some people and con to others.
80/20 is also very nice and a batting I use regularly and find just as nice as cotton only with a tiny bit more loft for definition of quilting stitches.
Here are links to two quilts I did with Hobbs Polydown:
http://www.quiltingboard.com/picture...g-t275921.html
http://www.quiltingboard.com/picture...c-t287411.html