nasal pillow vs. face mask

I have been using a nasal pillow and nasal mask for a week now, since I received my CPAP. I noticed I was still getting sleepy near the latter part of the day and noticed that I was getting about 5 ARI/hour. I thought I would try out the face mask that I tried out with a ResMed originally (and did not like-the face mask,that is) I found I felt more refreshed the next and not at all sleepy. I also noticed the 95 percentile pressure was at 6 as opposed to 5 with the nasal mask and pillow. Is there an efficiency difference between the nasal and the face mask?
thanks,
tom

When you refer to a "face" mask, do you mean a full face mask - e.g the kind that not only covers your nose (as a regular 'nasal' one does, regardless of it being a cushion/pillow type or not) but also extends to cover your mouth? The kind that people who breathe with their mouths open when sleeping (which is what FF masks are basically used for)? If you are one of the people (and there are lots of us) then yes, a FF mask - not to be confused with a "total" face mask (only one on the mkt and it does cover your whole face, though with questionable results and very few customers) - will certainly make a difference in your results.

All masks are designed to "Leak" some of the pressure, if they didn't you would be rebreathing the same air until the was no O2 left only CO2. This may account for the difference in 90% pressure readings you are seeing.