I have the Back n' Belly
body pillow, and it's been a huge help. DH and I have a queen bed, and it takes up about 1/2 the bed, but it seems to be working out.
What I like about it so much is the fact that I don't have to readjust everything when I want to roll over. Same with getting up all the time to pee, the pillow stays as it is (I do have to push a "leg" of the pillow over the side of the bed to get out...). I also like the contouring of the inside of the pillow- it isn't a straight tube, instead it curves out at the waist to support the bellly and back.
What I don't like about it is that is't not very soft and fluffy. I also find the cover to be a little rough and wish it was softer. Also the curve of the upsidedown U (where your head rests) the cover is pulled fairly tight, and at first it would feel like it was cutting in to my shoulder. That feeling seems to have gone away.
I also like the upsidedown U shape as opposed to the C shape because it's really nice to lean on when laying on your back. I put a pillow at the head of the couch, then prop the body pillow on top of that, and sit in it, resting my butt in the open spot that the curve creates. Keeps me elevated a bit so I'm not completely resting on my back, but is very comfy. It also looks like it will be good for nursing, can use it like a boppy if you lean up in the curve and wrap the legs around your waist.
So that's my review- there are things I don't like, but DH and I are both sleeping much better since we bought it! Worth the money!