So short impressions mostly from usability perspective.
Disclaimer: it may sound as I am nitpicking and this is negative review, but to be honest I really like this device, functionality, niche place it has in the market and how it fills this place. If the BT connectivity turns out reliable it may have a chance to replace my favourite audio source of all time Qudelix 5k.
- this thing is very cute, but extremely small. I am a sucker for small devices in general for portability, and modern high end DAPs are my worst enemy because of that, but this is on the opposite extreme of the size. It may be too small. My thumb is like one third of the screen size. The fonts are very thin and small and connected with low Res screen they are barely readable. Reading long song titles is pain in the ass.
- the size gets me plenty of perks on the other hand - it just blends in my pocket (which may be a bad thing as you may loose track of where it is). It does not weigh anything so it does not pull my pyjama pants down while night cooking

. It is perfect for bed as it is not likely to hit me in the head or to drop on the floor getting destroyed or destroying my tiles as some M17s or DX300s would do. It also fits snuggly in my IEM case with pair of tips - PERFECT
- overall user experience is not perfect coming from Sony ZX300a DAP. There everything is basically 3 clicks away. In M0 Pro to get out of the play now to playback option you need several swipes. Also it is not buttery smooth in here.
- battery seems really good, but need more testing - after 2-3h of mixed listening (IEMs on low gain, high impedance buds (500Ohm Serratus) and 24h of standby I lost one bar.
- did not test the BT connectivity yet
- the sound is on par with my other portable devices at least like Qudelix5k, Sony DAP. No nuance is lost, bass is tight, dynamics are great, nothing is softened or oversharpened. Just like a transparent source (as it should be IMO). Did not compare with DX3pro+ yet.
- it can drive anything I throw at it sufficiently. IEMs like UM Mest OG, Xinhs Erasmus are obviously no problem on Low gain, 500Ohm Serratus on single ended (no adapter at my distributor) I needed to push at 70% high gain and it still sounded pleasing. I think that on balanced I feel more comfortable though.
- build quality is almost perfect. One small nitpick is the volume wheel sometimes skips, is somewhat loose and not clicky enough (at least comparing with Shanling Q1).
First impressions: 9/10. This is probably not a perfect device for most hardcore audiophiles, but for what it is apart from some minor quirks it does what it is supposed to do very well. Probably also the target user is more someone from general consumer market treating this as an entry device to the high end audio. And here M0 Pro also fits like a glove.
I attach pictures for reference.