I have started using wool batting lately and love it, especially in larger quilts. It maintains it's loft and is soft and drapes beautifully. Poly batting will lose it's loft after a while leaving the quilt looking frumpy. Dream Wool (I think that's the name) can be quilted up to 10" apart. It's a bit more expensive (can't get it at Joann's with a 40% coupon) but when I have made a really nice quilt using good fabric it's worth it.
I agree with her totally. I only use wool batting and love how it looks and feels. I use to use 100% cotton but my quilts were stiff and very thin. Now, all my quilts with wool batting look lovely and feel wonderful.