Well, I did end up taking a nap yesterday. A long one. Even by my standards. So sleep was not easily forthcoming when I finally went to bed. I ended up reading until about 3am before I felt like I could even try to drift off. Which is ironic since the novel I was reading had a scene where the protagonist/narrator reads a Sue Grafton novel until he can't keep his eyes open anymore.
Haven't read Sue Grafton since I or J, in case anyone is interested.
Woke up a few times during the night. Fewer mask problems this time, although when the pressures gets sort of high there's still more leakage than I'm happy with. Also the noise of the air whistling through the vents, which is pretty quiet at 5 cmH20, is actually kind of annoying, except it masks the resonance of the air moving through the hose, which is sort of annoying when you're trying to breathe regularly and clear your mind. But it's great for playing spaceman.
Sleepwise is a five again, but awakewise is probably a six. I've been up for a couple of hours now and don't feel like I really want to go straight back to bed, which is a leg up on yesterday. Doing a couple of loads of laundry this morning (well, it's noon now), which is making me feel very productive.