I have taken one. They attach all these wires to you, video tape you while you are sleeping. My doctor wants you to sleep on your back which is something I don't do much of. They can talk to you without coming in the room and I know they awoke me at least once so I would lay on my back again. (not all doctors insist on this). They wake you up early and send you home. (my room had a shower in it but I just wanted to go home). I didn't feel like I slept well at all.

They study the tape and you go back again and try out one of their machine called a c-pack. The first night all the wires etc. show them how often you quit breathing, etc. I quite breathing 47 times each hour. This time they hook you up again but you are now using the machine. I had trouble falling asleep with this thing on my face. So they gave me a sleeping pill. I made it through the night but did not want to get up and go home. The bed was quite comfortable, the person you deal with is quite nice. The only time I saw the rest of the group was on arrival because we had to wait until the doors opened. The second time I was late arriving so I ended up not seeing anyone. It is not a "fun" experience but it is not a "bad" one either.