I've quilted queen size quilts using cotton and wool/cotton blends and the clients said they were too heavy. One was undone and had to be re-quilted without batting. The other, a friend, got me to make another quilt and finished it without batting. both were happy with the results.
I have also used minky ( so soft) & polar fleece, which I didn't think was any heavier than the traditional battings.
The last few quilts I used what I'm told was micro fleece, which isn't as thick, but is as warm as the normal fleece. It wasn't the best to quilt as I had to lower the foot to avoid skipped stitches, and the foot stuck on the denser piecing joins, upsetting the stitching, but I thought it was a bit lighter to carry.