I have used the CPAP seal for about 2-1/2 months and had good success with it. It's a bit tricky to get it lined up, but once I do, it works great for me.
My pressure is up around 20 and my goto mask is the Resmed Mirage Quattro. I also use the Simplus mask. the first thing you must do is to fit the mask at the highest pressure that it will see. I understand that the mask fit feature will allow you to accomplish this. The common practice is to leave the forehead stabilizer very loose. Due to the fact that the bridge of my nose is set back pretty far from my forehead, I need to get the forehead stabilizer fairly tight against my forehead or the self adjusting seal at the bridge of the nose will not reach my nose well enough to seal.
I played around with cushion sizes. The sizer said that I needed a medium so that is what I got initially. After trying it for a while, I decided that I wanted to try something that sealed further down my nasal bridge so I tried a small. I did some comparison testing and decided that I was less prone to leaks with the medium. The medium rests in the notch between my lower lip and my chin (with my mouth completely closed) and the seal at the nasal bridge is right up against the rise from my nasal bridge to my forehead.
One thing that I found that reduces the fiddling that I must do to minimize leakage is as follows. When I put the mask on to go to bed and I turn the machine on, I wait until the pressure comes up and then I pull the mask slightly away from my face so I just start to get leakage most of the way around and then I lower it back onto my face. This ensures that the seals get fully inflated which gives them their maximum sealing power.
Another thing that helps some people maintain a seal is to remove the skin oils from their face in the area that the seals are going to rest on. You need to have good friction between your skin and the seal or it makes it easier for the seal to blow out.
And yes my straps must be reasonably tight. At higher pressures you can forget about "float like a butterfly" but you sure better "sting like a bee". But only tighten your straps as much as is absolutely necessary.
Well that is about all I can think of right now.
Hope some of this helps.
Last night with my rubber band mod I did get some leakage at different times in the night
A value of 6 at 95% , including 5 large leaks
It allcame in a couple of bursts
Looks like I may have had a bit of mask trouble
The straps were tight , I am still seeing the indents on one side
My ahi went up to 3.3, up a bit.
i guess the main thing is I slept and did not spend all night fussing with the mask.
As mentioned due to a nose break I wear the masks just below the bridge of my nose, this causes the bottom of the mask to sit at the bottom of my chin just below where they recommend
I may try a small mask to see how that goes but reckon that it would be to small
The small is just shorter from the nose bridge to the chin.
I used to use this mask, to get a seal on the bridge of my nose I would turn on the pressure, lift the mask slightly and pull it towards my chin with bridge seal in full contact with my nose. This would put more force on the silicone that forms the nose seal and get it to set better.
This is also the reason I switched to the Amara View, could not tolerate the nose pressure very well