Tried to set up Syncthing for music - actually the primary reason I went with an Android based player - but was disappointed to find out Syncthing doesn't support SD card storage. Setting SD card as internal storage is a workaround, but the Android version on the player is missing the 'format as internal' option. Bummer :(
I was able to disable most of the google stuff though, which is a neat. F-Droid works nicely, and grabbing apk from non-Google app stores/sites is pretty straight forward. Although somehow system search relied on google service - hmm, makes you think, right?
Battery life is not stellar - but something I can get used to - I got to 50% after 8-10 hrs of listening to a mix of flac/hires flac/aac. I mean - back in the day we didn't have to charge our phones for weeks, but look at us now. It does finish charging within 2 hrs or so with a fast charger which is nice.
I like the fact that USB C port is on the side, no more weird protrusion while holding it on the table.