Here is a youtube review of the two big onyx readers (10'' and 13'').
Note: the very last 10'' reader (boox note pro) has now light feature.
You'll see that the soft is fast and that it is well conceived (I especially like a lot the cropping zoom option that allows to get rid of the empty spaces around the text and get a bigger picture size).
https://www.youtube.com/watch?v=2Bjr9dws2Vs