I had one. It was at a hospital, but the room was set up like a hotel. They even had a Sleep Number bed so you could set it where you liked (great idea for a place like that!)
I felt like I was awake all night long, feeling really conscious of the wires and everything, not being comfortable for more than a couple minutes. But apparently I did get about 5-6 hours of sleep. It wasn't bad at all, just awkward because you are so aware of the wires and so actively trying not to think about them - which of course makes it worse.
Turns out I have mild sleep apnea. My doctor recommended that I try this mouth guard device that pulls your jaw out a little bit to keep your tongue from resting in the back of your throat. I was/am really against the CPAP (I know they work, but I just can't get myself to do it and my apnea's not that bad to force me to do it), so I thought I'd try it. I hate wearing it, but it seems to help, although I do still snore with it sometimes.
I haven't worn it since the boys were born, though, since it's awkward to be awake with it, and I'm up too often at night to feed them. To me, I don't feel like I sleep any better with it (I'm often still tired when I get up, but between pregnancy and babies, it's hard to tell if apnea's the cause), but I know DH usually does.
I'd really love to have the surgery to fix it once and for all instead of messing around with equipment.