Must be the quietest PAP mask on the market! Just compared it to the new version F20, and it is quieter and softer at the vent. Have had difficulty finding a full face / hybrid mask to fit as I am XS in the cushion and in the headgear. This one seals well for me and comfortably - admittedly with F20forHer headgear that has been sewn shorter. The XS F10 cushion tends to be very narrow at the bridge and wide at the mouth - which seems to limit the nasal breathing I can do. The XS Evora FF is usable but the headgear I could not adapt small enough. The XS with forehead frame all did not allow cushion to be firmly/even enough in contact with face. The XS Mirage Quattro had the best seal but much less comfortably - and appears the same size and shape as this one. Note that I found the F5AS cushions to seal better than the F5A; the F5A having visually, marginally less wide cushion contact area. Hope BMC keep this one on the market for many years to come!