I looked closely at them, but after trying them out I chose not to go that route because:
They were soooo expensive.
You have a difficult time turning over. I mean it's REALLY difficult. Try it and you'll see what I mean. I guess if you constantly stayed on your back or stomach it would be OK.
I chose instead a Stearns and Foster that while still a little pricey was just perfect.
Hope this helps.