Let me just say that waterbeds are very very nice.
The man made bold claims - you sleep more solidly, you don't wriggle to get comfortable, you wake up more refreshed, you don't get too hot or cold - and I can confirm all his bold claims.
Takes a couple of days for the mattress to settle once it has been set up, and you need to make a few adjustments of pillow height, adding/removing water (we haven't done that yet).