I love the small size and how it simplifies packing and the air travel experience. My main machine is an AirSense 10, which is not bad for portability, but the AirMini is much better. Everything fits in the little draw-string bag. It takes much less room in the carryon (and doesn't have to BE the carryon), and it is easily removed for the screening process. It also takes up almost no space while in use, which was nice at my destination.
It is not as quiet as the AirSense 10, which can hardly be heard at all, but the sound posed no problem for my wife. She is a light sleeper, so this was a concern.
The moisture-retaining filter fits into the mask and is tiny, about the size fo a quarter. I have not used it yet, and the lack of humidification was not a problem on the trip I just completed. They recommend replacing this filter after 30 days from the first use. My trip was short, so I didn't start the clock on the filter.
If you want/need to customize the settings, it must be done through the phone app. Accessing the clinician menu settings there is hidden. (Tap the BlueTooth icon at the top right. Hold down two fingers on the ResMed logo.)
Note that your sleep data on this machine is not combined with that of the main ResMed machine. This could affect your provider's monitoring for "compliance" if needed (e.g. for Medicare).
I highly recommend this machine for those who want easier travel with CPAP.