I'm not sure he'll ever admit to the 'wow' factor but he finally realized it was making a difference a few months into it when he DIDN'T use the cpap one night and was immediately exhausted. He's never gone without it since and will even travel with it.
He finally had energy to exercise and make better eating choices and has lost a lot of weight, went from being pretty taciturn to happy, has someone very special in his life, is moving forward towards building a life, etc., something he was incapable of seeing before. It's very wonderful.
I'd always heard from others how much a difference getting their sleep apnea under control made in their lives but it was still amazing to see it in my own son.
We realize now that his began as a child and though we tried to get help for him then, doctors weren't really paying attention, nor did we realize just how bad it was and so didn't push as hard as we should have. I'm just so glad he finally got the help he needed with a doctor who didn't dismiss him because he was overweight. What a change it has made for him and for all of us.
So hang in there. I know that, for him, so much depended on finding the right mask, humidifier, etc., before it all finally clicked. AND looking back to see how far he had come.