How does Boox compare to Kobo?

Hello - looking for my first ereader and had some questions for anyone who uses Boox as an ereader, or if you switched from a Kobo device to Boox, to draw some comparisons.

I'm looking at a Boox to primarily use to read non-fiction books, textbooks, and maybe PDFs. I will annotate a lot(highlight, write in margins, circle, etc), so annotating abilities is important.

I love that you can annotate in the margins and even expand the sides of the book for a larger space. Like the idea of it being android based since I can get both the Kobo and Kindle book library to buy from. Also imagine if I get ebooks from online, I can use Calibre to deDRM and read it on Boox. I don't mind if I need to deDRM Kobo/Kindle books and use a separate reading app in Boox.

Was wondering if anyone could shed any insight into:

1. Annotating features - does it work well with all books? or is it better use the built-in reader?
2. Also debating on size, I know this is subjective, but would the Go 10.3 be too big? Also was considering the Air5 C or Tab X which are bigger, like the option of colour, but it's not necessary. Functionality matters more.
3. anything else to consider as a primary ereader?

Thanks for any insight!