How to collect information for sleep analysis?

I have a Resmed 11. How can I assess what affect it is having on my sleep? The information provided on the MyAir app doesn't give me a sense that it is meaningful nor accurate.

I used to have a Withings Sleep pad, but it too seemed like a toy.

Aside from the same medical-grade tools used for my initial sleep study, how can I gather and interpret the data to be able to compare between nights using the CPAP and nights without the CPAP?