RE: Liz's CPAP therapy
Yes, at least for my part I noticed my therapy was markedly worse when using FFM than nasal mask. The idea is that you keep the pressure in the upper airway with a nasal mask, and this keeps a pressure differential to your soft palate and other structures in the mouth, vs allowing the pressure to equalize in the oral cavity as well. That being said, everyone has a slightly different physiological reason for their obstruction, so this may not make much difference to you, or it very well may be a noticeable change.
Look, I'm an engineer, not a doctor! Please don't take my opinion as a substitute for medical advice.
RE: Liz's CPAP therapy
That's very interesting. This is off topic but I was just helping a friend try on masks before a titration test. She has major throat and larynx issues (can only talk in a loud whisper and needs regular botox injections in her throat even to get that). She kept holding her breath with the hybrid face cushion but adapted well to the nasal pillow. I thought it was because the face cushion had a slit and the pillow had gel nubs, but now I think that pressure in the mouth and throat was too much. (I've been encouraging her to push for oxygen treatment and sleep studies and tests for over 6 months. Her oxygen is going super low, low 80s during the day and lower at night and she even passed out a couple times, which they called a mini-stroke without even an O2 eval - but hopefully she is finally getting treated after the titration test Thursday. argh.)