I'm a side sleeper so the mask isn't too much problem. I tried some different masks but find the full face with the memory foam to be the most comfortable. Airsense F20 I think. It doesn't fit quite right but it is the best of the ones I tried (pillows, etc). Many setting changes have been made and while a little better, it is still not working (meaning I don't get more than 2ish hours of sleep). Oddly enough, when I was in the lab doing the titration with bipap (not cpap or apap) I slept the longest (about 5 hours). I was super happy and thought that this was the answer as the cpap didn't work for me. But, alas, the home machine is nowhere near the lab machine even though they say it is the same. I don't believe it.