I'll offer something I learnt – I guess it may already been written somewhere here.
A solution for noise etc.:
A hole in the wall behind the bed – pipe through the wall (sealed) – machine in the next room with a remote switch on the bed-wall.
Benefit – I don't hear a thing, even though the CPAP is only two feet from my head..
As luck has it, the room behind is a fully tiled bathroom. The machine is in a small vented wall cupboard there - practically dust free.
This room is of course always warmer and damper than the bedroom, so I never need a humidifier. In winter I can have bedroom windows wide open and still breathe no cold air.
I just disconnect and use a spare pipe for travelling.