First up - Where is the language setting?
The M5s arrives set to Chinese. Clicking through the menus doesn't show anything resembling language choice. Finally it dawns on me that the menus scroll down - the GUI is not familiar - and the language setting is fourth from the bottom - after scrolling the gear menu down all the way.
Downloaded firmware V2.1 over wifi. Painfully Slow!
Manually updating the Music Library is slow - several minutes for a 35gb collection. Haven't tested automatic update.
Mounting as USB on Windows only works as the D: drive even if something else is mounted there!
Bluetooth pairing is flawed. It paired easily with Edifier S1000DB but took many tries with Edifier S2000 Pro. Two tries to pair a 2012 Camry, but the artist and title are not displayed and only play/stop work.
Playlists can't be renamed on the unit but can be created as Playlist1, Playlist2, ....
Recordings I tried - flac, mp3, mp3 vbr v0, wma including:
Growing Up in Hollywood Town, West of Oz- Lincoln Mayorga & Amanda McBroom
Crystal, The Legendary Okeh & Epic Recordings - Ahmad Jamal
Jazz at the Pawnsop - Arne Domnerus
Aja - Steely Dan
A Rainbow in Curved Air - Terry Riley
Time Out - Dave Brubeck
Rickie Lee Jones
Skyline -Bobby Hutcherson
Overall I'm very impressed with the sound.
Headphones:
Connected to DT770-Pro on high gain, unbalanced, volume 90, the sound is clean and crisp. Lesser amps - Realtek HD Audio, Fiio E6 - don't have the power to control the DT770-Pro. It gets a bit warm driving these at reasonable volumes.
Connected with KZ ZS7 iem the sound is clean, clear and precise - most comfortable and engaging sound of everything I've tried so far.
Overall usability is fair, sound is excellent.