Years ago I used a duvet cover and to get the comforter back in after washing I had to crawl in to the slit of the duvet cover to get the comforter in place. What a pain! I didn't have problems with it shifting though between washings. I got tired of the whole 'putting it in place' thing though, and quit using duvet covers. Now I just have my comforter laying on my bed in all its glory! I've found down comforters in colors, but never found one with pretty embroidery or print on its shell. I'd love to have one with delicate embroidery and a hint of pastels in the design, and I don't understand why such a thing isn't out on the market (unless I'm just missing it).
Hah, I have to do the same thing! Luckily, I don't have problems with it moving since my bed is against a wall, so I tuck that part in between the bed and the wall.
I hate duvet covers with a passion though, if I could find a nice pink/white striped comforter like the duvet cover I have now, I'd be a happy person.