I got my new Fisher and Paskel 432 mask last night. I'm sold on the full face mask since I first tried one. I let air leak of out my mouth so I need a chin strap which is really a pain literally -- thus I've got to full face mask.
And like all CPAP mask users, I'm on the search for the perfect mask. The one seems closer than I had before. At first I was disconcerted because it hissed, but I figured out quickly it was the rebreather -- the silicon was stuck. Fixed that, and had no problems.
Was able to wear it through the night. The biggest test will come in 7 days -- we're seeing 50 minutes of leakage every night, and the machine only shows a 7 day average.