I think this mask is one of the more successful full face masks.
Let me give a rundown as to why I think it is superior to the others I've tried:
Pros:
1. Exhaust flow rate (EFR): For a pressure of 11.5, it should be somewhere between 30 and 35.

My 95% leak rate averaged about 41, but was closer to 35 for the first half of the night. The EFR on my UMFF is about 50 for the same pressure. That higher leak rate seems to mean slower response times by the machine when it comes to air pressure regulation. That lag in response causes a considerable amount of aerophagia for me in any position except when I'm on my back when using the UMFF. I sleep in a lot of different positions, so the aerophagia tends to wake me up as much as any apnea or hypopnea might. I did not experience any aerophagia with the lower EFR on the zzz-mask, apparently because the machine can respond more quickly if there isn't as high a leak to guage pressure relief against. I was able to sleep in any position without experiencing aerophagia with the ZZZ.
2. The mask is mostly silicone with a rigid frame that's only a very thin brace to keep it from expanding too widely. Here's a picture of the mask with all it's pieces separated, sans strap:

Here's the frame close up in my hand - it looks very fragile. Hopefully it will stand up to my tossing and turning:

That means the whole mask is entirely flexible:




3. The pillow part of the mask that sits against your face is not polished, but instead has a matte texture that seems to help keep the mask from slipping around as much when you sweat.
4. The nose bridge, along with the rest of the silicone gradually gets thicker the further you get from the edge of the pillow. The end result is that instead of having a thin bit of silicone bumping against a rigid plastic frame, you get more resistance directed into the silicone itself, spreading out the touch spot over a wider area on the nose bridge. Force against the bridge is more evenly distributed, alleviating the sense of pinching on the nose bridge.

5. You can wear glasses with this mask.
6. The upper plastic struts of the frame end up keeping most of the straps off your cheeks. They also evenly distribute the force of the straps pretty well across the face.
Cons:
1. The straps on either side of the frame act a little like horse blinders to your lower peripheral field of vision. You end up looking through the plastic struts that hold the straps.

2. Just like the other masks, after I get up at four am for a restroom break, it doesn't seem to fit as well, and I end up with a little more leakage from the sides and around the mouth.
Overview:
The cpap.com measurement tool suggested I should buy a medium, but the zzz downloadable pdf gave me an impression that I'd be better off with a large.
Of all the masks I've looked at or tried, this one seems to come closest to ideal. The straps had to be cinched very tight in order to stop the leakage around the mouth - something that seems typical for all full-face masks - but it was achievable, and didn't leave me with a headache at the end of the night. I used a pap-cap to prevent mask torque and keep my mouth closed, but I suspect this mask could be worn without a pap-cap and you still would have pretty low mask torque if you don't have trouble keeping your mouth closed.
This mask cradles the nose and the nose bridge better than any other mask I've tried. However, I wish they'd make a mask that curved around the cheeks near the edges of the lips better.
I've only had one night using the mask, but so far, I'm glad to have purchased it. In a week or so, I'll come back with a fuller assessment. To see more images, go here: http://www.montfordhouse.com/images/cpa ... slideshow/
I don't know if this will help someone else, but hopefully, it will give others a good idea of what it's like to wear the mask.