I went the Boox way more than half a decade ago. Personally, the 2 draws were:

• The availability of bigger screens: at 10.3'', the Note 1 was great for A4/Letter PDFs, and I just liked to have a big wall of small text for my epubs.
• The freedom from walled-garden: I could use whatever Android app to read whatever format.

Other will probably tout the note-taking, the possibility to use a real browser, the versatility of an e-ink tablet, etc. But those are not my main use case.

They are on the expensive side though, and my very plasticky Note 1 sadly died after only a short handful of years. The latest Boox offerings have metal casings though, so they might be more durable.

I've been reading on my mobile since my Note 1 died, but I could finally splurge on a Go 10.3 recently. That big, non-backlighted screen is glorious and so restful after a day on computer and mobile screens ❤️

For my next one, I might go bigger (13'') and colour - if colour e-ink improves markedly - for comic books consumption. But I hope I can rock the Go 10.3 for the better part of a decade this time 🤞

(PS: Calibre and ePub for the win!)