I hand quilt so I prefer poly batting -- but the big reason for me is that it doesn't shrink at all when washed. I like my quilts to be unwrinkled and smooth.
Most people seem to like the vintage wrinkle look.
I tell the recipient that if their quilt isn't worn out in 25 years, they didn't love it to pieces. -- That makes them relax and not be afraid to really enjoy their quilt -- Mim