Just added the two new Boox devices to compare: the Boox Go Color 7 and the Boox Go 10.3.
The Go Color 7 looks like the Boox alternative to the Bigme B751C, (comparison
here) - no stylus support though, but it's lighter, has a newer Android version (12 vs 11), is 'water-repellent', and has a G-sensor to auto-rotate the screen.
The Go 10.3 looks to be mostly competing with devices like the reMarkable 2 and Supernote A5 X (both of which also don't have a frontlight), so mostly a lightweight note-taking device for daytime productivity use-cases. Boox using Android and having the Google Play store is an advantage.