I have used duvet cover over a comforter for many years…with a quilt to cover it neatly. In the last year or so, I toss and turn so much that the cover and filler piece shift too much, leaving it a messy and uneven . I took the duvet cover off this summer and I don’t even recognize the mess of a bed I wake up to every morning. I would love to find a flannel comforter…not comforter cover. I have yet to find one…it is all an issue because of my hot flashes