I've used thin batting with minkee and I was happy with the results.
I recently just did my first quilt with just fleece and no batting, it's ok and the fleece was fine to work with but I think I would like it better with a thin layer of batting. In my case I used a dark fleece (Seahawk logo on dark blue) it worked ok with my quilt top (sailboats on a light blue background) but if I did it again with a light top and a dark fleece and no batting I'd probably put a piece of flannel or muslin in between to stop the color bleed through.