I am proud to say I have two bed partners - my wife and my CPAP.
The quality of sleep you get is absolutely amazing!!! The masks are a bit weird but you have many choices and the sleep clinic I have dealt with is absolutely top notch. They call me about once every 2 months to see if things are going well.
My first mask was a partial face mask where only the nose was covered. At first, it was fine, but then I got into the uncontrolled habbit of letting my mouth fall open during the night and the necessary air pressure was not maintained. It just blew right back out of my mouth. I then switched to a full face mask and it solve the open mouth problem. Now I am sleeping better than ever. I am firmly convinced that using my usage of CPAP has improved my insulin sensitivity.