Looking only at the self-promoting video at the Sony website, I'm a bit worried about the contrast of the display. The background is quite grey...
https://store.sony.com/gsi/webstore/...2FHVavA8FOFTe2
The video would like you to think it's better than paper for lots of think but what strikes me in this vid is that I can't read so well than on the paper due to this apparently low contrast...
I had the same problem with my PocketBook Pro 903.