OK, I have two experiences to relay, my own and my co-worker, Debbie, who also is trying the same model of MAD.
My own experience: I molded my mouthpieces according to directions (definitely, absolutely READ THROUGH the instructions several times to make sure you understand it, and also VIEW the video that you can download, and they suggest practice first which I also think is a good idea). I got a perfect fit the first time, but then I second guessed myself and decided to trim off some of the excess, which I regretted because then things didn't fit as tightly. So I went back and started the process all over from the beginning. I would have been in big trouble had I gotten the Classic or 2.0 version because you can only remold once or twice. The AP, which is what my co-worker and I got, you can remold as many times as you want. I finally got a good fit (not as good as that initial fit, but good enough), but will probably take it back tonight to boiling water and smooth some edges.
It definitely feels bulky, kind of like when you were a kid and would bite into the pulp of a quartered orange and made monkey faces with your lips opened to show the world the orange peel. Definitely hard to pull my lips closed over it, but maybe other folks won't have that difficulty as I have a small mouth. It was a little awkward trying to figure out where to put my tongue, but where I finally put it is where I think you tongue really should be anyway when you sleep, and all the plastic molding material that had oozed up onto the palate from the top mouthpiece and oozed downward from the bottom mouthpiece actually helped to hold the tongue still.
It was easy to mouth breathe if I wanted ... you can't do that very well with the Classic or 2.0. But I think I did all my breathing nasally.
I was concerned about the drool, because I definitely felt the saliva pooling in my mouth. But it wasn't really a problem if I slept on my back or mostly on my side. The saliva just pooled in the mouth and stayed there unless I swallowed it. The only time it drooled out is if I slept on my stomach or turned far on my side. I figured I'd put up with a damp spot on my pillow if it meant I'd get good sleep, so I really wasn't worried over it. The thing that I did worry over with the drool was the idea of choking and drowning on it. But that is an old phobia, as I've several times in the past stupidly inhaled a little spit and choked bad enough I thought I truly was going to suffocate. So it's probably just a mental thing for me.
When going to bed, my jaw was sore. I was pretty sure it was simply me tensing my jaw, which I do tend to do in normal situations. But I did that meditation thing where you pretend like a part of your body has lungs, so you "breathe into" that part of the body (so in my case my sore jaws), then "breathe out from" that part of the body. Within about 5 minutes all jaw discomfort was gone after doing that. Any time I caught myself again tensing my jaw, I did the meditated breathing again and it always worked.
I had a hard time falling asleep, but it wasn't due to the MAD but because my teen son was up late on a school project, and I kept telling him I did NOT want him pulling an all-nighter on it. The light coming in from the living room was keeping me up. I couldn't close my bedroom door, because our daughter neglects her kitty by often shutting him out of her room so he's adopted me as his "true owner" and will push and scratch at my door to get in, so I have to leave it ajar for him or I'd never get to sleep because he's obnoxiously persistent. He really loves me though, and as a nighttime-wind down regularly brings me his mouse toys into my bed so that I can toss them across the room and we can play fetch—it's really funny when he loses ALL his mice and comes to me asking about them There's 14 missing mice, and we've looked everywhere for them, very clean house—someday we're going to get a laugh when we find a strange nest of toy mice somewhere.
The hardest thing getting used to was that I really couldn't maintain keeping my lips closed over the mouthpiece. If I slept with my hand up near my face, the weight of my hand could sort of keep my mouth closed. But I stopped worrying over it and went ahead and allowed my lips to be in whatever position they wanted. This was the worst thing, because I was bothered by dry mouth because of the lips being open. I think I may have to put oil or ointment on my lips to deal with that. It was also awkward about how far apart the teeth on the top were kept from the bottom due to the added bulk of the mouthpiece between the upper and lower jaws—awkward, but soon ignorable.
When falling asleep, I did feel waves of relaxation just wash over my body. That was really nice, since I've had chronically tense muscles. And my airways definitely did feel nicely opened. My throat around the voicebox and thyroid felt nicely relaxed, too—even when in the past week when I was choosing positions to sleep that opened up the airways my throat had parts that felt tight or tense, so this discomfort was gone.
I did get some soreness in my front teeth, especially the lower ones, but nothing more than what I experienced when I had retainers after braces as a teenager. The information sent with the MAD says some people do, but it will go away within 2–3 weeks at worst (it's a rare case that it doesn't or gets worse).
I did dream about about the MAD, about remolding it or about popping it out of my mouth and then putting it back in. But those dreams about popping it out, I clearly remember telling myself there's no reason to remove it, that it's actually comfortable, and to put it back in. So I definitely think I'm mentally dealing with this even in my sleep. :)
On getting up in the morning and removing the MAD, my bite was definitely different, with the lower teeth extended just slightly beyond the top teeth. And it felt very natural. But don't let that alarm you. They did say in the instructions that that happens but will revert back to normal position within an hour. I had to deliberately pull my jaw back and chomp up and down a few times, but that was enough to remind my jaw of its normal position, and everything was definitely back to normal in less than an hour. The tooth pain I had also was totally gone within 15 minutes of removing the MAD in the morning, so I think that will be permanently gone within a few days and won't be an issue when I sleep as I adjust.
The instructions also say that the feeling of having a "foreign object" in the mouth will totally go away within 2–3 weeks. I started getting comfortable with it well into the night, so I think it will only take me a few days to get over the "foreign object" feel instead of weeks.
Like I said, I'm tired this morning, but I don't think it was the MAD but my son staying up way too late. I did toss and turn less, and restroom runs were just one. I'll post back after I've had a little more experience with this (not sure if I'll do a day by day or not—will depend on if there's anything significant to report).