This device solved my problem of my CPAP machine's humidifier running out of water in the middle of the night every night. I can't think of a better way to solve that issue outside of Resmed redesigning their machine.
It does have one rather frustrating aspect, though unrelated to its function - you can either have the blindingly bright white LED power indicator and in-tank "mood lighting" on or off - when it is on, it lights up the room, and bright white is the absolute worst color temperature for sleep, like having an always-on mini wake light on your nightstand; but if you set the light to off, the unit is visibly indistinguishable from being entirely turned off, so, if it were to lose power for any reason, you would have no way of telling beyond your tank being empty in the morning.
I don't know how anyone thought it was a good idea to have the power indicator be a bright white halo of doom, or to have disco lights in the tank. All it needed was a simple, small and dim LED, ideally red so as to not mess with your circadian rhythm or dark adaptation, to show that yes, the device is on. But the only options available are party-time illumination or nothing at all.
Don't get me wrong, everything related to its actual functional purpose is great - but I shouldn't have to sleep with a sleep mask every night because of my CPAP water tank.