Looking at my sleep study...

[Sleeprider]

When using the P10, spreading the straps wider apart on the crown of your head results in a looser fit. Hopefully you were using the large size pillow.

[Aludj]

I did not use the large size, the medium one was a better fit.

Yes, the only adjustment with the P10 is to spread the straps wider. When I did it to the point, where the pillow was comfortable, the top strap easily slipped forward and the pillow got loose. I am not the only one, who had this issue. Other people with hat size of 7 7/8" experienced the same.

I didn't give up on it yet, just needed couple of good night sleep...

[Aludj]

I had an oral surgery, that pretty much prevented using any other type of masks, but the pillow. At this time, I listened to and tried the large size pillow. Well...

The large pillow is more comfortable than the medium sized one, thanks @Sleeprider. The headgear is still a bit too tight, but either I'll modify it, or with time the headgear will loosen up enough to be comfortable. I still dislike the noise it makes and at times, prevents falling asleep fast. This image from last night is indicative of the large pillow performance for the last three or four days:

   

Please note min/max pressure. I did adjust the minimum pressure to 10, but dialed it back to six. This pressure setting is comfortable with the pillow mask.