I've been experimenting around with my older masks, an N30i and a F&P Brevida. I'm wearing each one for a week at a time and letting the machine adjust the pressure. On those 2 masks, my pressure is usually around 7.5 cmH2O, but when I use my Bleep mask, it's usually around 5.5 cmH2O. That seems great, but then I'm wondering. 1) is this because there's a lot fewer outlets/bypasses on the bleep mask 2) if so, how much less CO2 is purging from the system when I exhale?