This morning I woke up after eight hours' fairly solid sleep, and the S9 said I had an AHI of 5.5 -- not the best I've done, but the best I've done on a night where I slept for more than five hours. So I eagerly went to get the SD card and look at the details in SleepyHead, and found that I hadn't actually clicked it all the way in to the machine! So no detailed data, and no graphs.
Be careful what you wish for!
(To all those mysterious one inside and outside my head who may be listening, I haven't reached the boring reliable part yet. I'm still way more tired than I want to be, and I need those graphs to get all the way there. Thank you.)