I've had my old Remstar for about 8 years now. It came with a full face mask that I never could get use to, sore nose and I couldn't turn on my side without it leaking. Went back in after a week and they gave me the Adam system with nasal pillows to use until they could get some more masks in that were my size.
The nasal pillows worked perfectly and I never changed back to the mask. I can sleep in any position but on my stomach, without any leaks or discomfort. I would give them a try. The Tech. said that I needed the mask and that I also had to have a chin strap to keep my mouth shut. Don't need either. the vacuum keeps my mouth closed without any straps and the nasal pillows work just fine.
I found out about this site because after 8 years, my head harness if wearing out and I ordered a new one today. All other original parts are still working and I've not even had to replace the pillows. Just clean everything regularly and it all works just as good as day one. I don't have a fancy machine with a card and humidifier etc.... Just a ramp system that gets up to 18.
I love my CPAP machine! It has saved my life and my marriage. I use it daily and I'm just now replacing the head strap after 8 years.
I'm curious about the other systems. Some look even less intrusive than mine, but if it ain't broke don't fix it, right?
Try other harnesses and face set ups until you get one that works. The benefits of finally getting it right will make up for all the hassles now.
Good luck.