I have both BP and use a CPAP. CPAP works for me. I forget how many times per hour I stopped breathing but I know it was enough that during my sleep study they quickly put a CPAP device on me. I wouldn't call it my best friend, but I no longer wake up exhausted from sleeping or taking a nap. I've slept without it a few times and came to regret it each time.

To further complicate things, I have chronic sinusitis with a deviated septum. One of my nostrils is completely blocked up. If I get a sinus infection and don't treat it right away it won't matter if I'm using a CPAP or not.