TLDR: Good experience with the Hisense A5
I have a Hisense A5. Had to root it and thought I bricked it at one point. But it pulled through 😄 It's now the only phone I (need to) use. Very happy with the change. It saves me quite a lot of eyestrain. The screen feels like the Onyx Boox screens in my opinion.
In comparison: I also tried an e-ink monitor (the Paperlike 3), but although better than the screen I had before, it was not great because it was too small, had too much glare, and I needed color more than on my phone.