The clever thing about Poly is that it has some more features and does the job using a mear fraction of the power with out loosing functionality or speed of operation .
As the author of Dapper, I have bought and run/tested a ton of DAP user interfaces and ease of use in terms of getting music and playlists to digital audio players.
This includes a ton of Astell&Kern, Ibasso, FiiO, Sony, Cowon, HifiMan models as well as some one-offs like the Pono, Onkyo, Phillips.
I don't comment on sound quality, since each person has their own taste here, but I do feel I have a lot of experience at which player performs in terms of:
Ease of connection (For example AK+Mac=Abysmal)
Music copy speed. (Some <2MB/s and some >60)
Playlist copy speed (Android players like AK and Onkyo with MTP are very slow)
Playlist pain (Can I just copy, or do I need to format each time)
Unicode character support (Does the player like strange character files? What about the strange file names in a playlist file? What if the file Unicode format <> file system Unicode format)
Playlist support in general which is a result of the above.
UI speed and fluidity
ID3 tag usage (Album art vs folder.jpg , strange characters as per above, volume tags)
Customization (Balance, volume, EQs)
Network connectivity (Android, WiFi, multiple SSIDs, OTA updates)
Streaming? Tidal? Android apps able to actually drive the DAC?
How easy is it to "sync" changes such as when you edit a playlist on your desktop, or buy a new album?
The Poly seems to be billed as having a ton of power, but with low-power-drain.
I'll be interested in providing usability feedback when she shipssince this is what Poly is all about...