> because it lets me syncthing notes

I know this probably doesn’t exactly fit your use case, but I’ve actually been able to do this with a Kindle Touch (yes, from 2011)! It was a super serene experience to have your books synced over into KOReader.

> if you try to use it as a generic android tablet you're doing it wrong

I agree, but I felt that’s what the system invited me to do (may just be my tinkerer genes though). Update notifications, etc, web browsing, hoops to jump through to share files ...

How‘s your note sync workflow? Can you reasonably easily and quickly access your handwritten notes from a laptop? Last I checked there was some manual export step to jump through.