I've been using the Bucky U sleep since they came out. This is a big improvement on my previous Bucky neck pillow. The cover is so soft and it's got more room to rest your head, no matter which way you turn. Honestly, I can't sleep at all without it. It's a five star comfort product.
I think it's kind of pricey to get a replacement cover for it, and the cover doesn't last all that long. I've had trouble with the zipper on two of four covers. Well, I guess it was more than trouble, since I could no longer unzip/zip it to launder it. Customer service is replacing at least one of the bad covers and they were very nice about it.
If you order one, I'd get a replacement at the same time, because you'll need one when you change the sheets, and you can't get one anywhere else. (It will save some postage.)