Results after the first night. Sleep didn't come easily. I changed to the 'full face' (nose and mouth covered) mask. With the nasal pillow variety, I just couldn't keep my mouth shut. As the night wore on, I got more used to it, and eventually feel like I got at least some sleep. The machine said I'd had an average of 22 'events' per hour. When my mind would wander, and I stopped thinking 'breathe out, breathe in' over and over, I'd get the sensation of not getting enough air and physically force a few deep breaths until the sensation passed. By morning, I think I had developed an 'uneasy peace' with the CPAP.
Comments here and the printed material that came from the sleep study, as well as included with the machine said that it might take 2-3 weeks to get used to it and like so many here, develop the 'can't get along without it' feeling. I'm still skeptical, but trying.
Jim