Fits really well, Ive only tried 3 masks so far but this one stands out as one of the easiest to use all night. Im a fidgety side sleeper, and have found that this doesn't leak out of the sides anywhere near as much as the others when I move in my sleep.
The quiet air valve works well, and once or twice ive woken up and had to check that the machine is actually on because it fits comfortably and its so quiet.
Replacing parts seems easy enough, as is the general maintenance.
The only thing ive found, which im yet to test, is the mask fitting... if you are borderline you may want to go up a size rather than down. The good thing is, its cheap enough and simple enough to change the cushion, and I gather the different sizes are interchangeable with the mask frame.
That leads into one of the other bonus points, its fairly cheap to maintain. At roughly £30 for a replacement cushion, its better than replacing the entire mask at over £100. I'm yet to put it to the test fully as ive only had it a couple of weeks, but my partner is a lot happier!