Only other consideration is perhaps how defined would you like your stitches? Since you are taking the time to hand quilt this - even big stitch - I would think your stitches would be better defined if using batting.
I'm just getting read to start working on an all flannel quilt to finish up for a friend of mine. Her stitching - very tiny, precise stitches - are still well defined. She used Quilter's Dream 100% cotton batting on her other quilts so I'm assuming it's the same batting with this one. It certainly has the same 'hand' as the other one I just finished up for her.
Just my thoughts.