There are also non-open-hardware solutions available, which reach even bigger sizes at 33 Hz and 3 bit per pixel, for instance from Dasung.

I have the “DASUNG Paperlike Color (Revolutionary)”, and I use it for coding. I works really well for that purpose, but I would not recommend it for anything else. That’s because it really only has 3 bits per pixel, meaning you get exactly 8 colours: black, white, red, green, blue, cyan, magenta and yellow. No shades of grey or anything, just those 8 colours in full saturation. For text (with disabled anti-aliasing - it makes the text fuzzy, but it is not needed, the resolution is great) that’s fine, for anything else not so much. Also, the contrast of the colour display isn’t too great. It either needs sunlight, its built-in front-light, or a desk lamp. It is also worth noting, that (at least the colour) Dasung screen does not have any display modes at higher bit-depth.

I also have a Boox Mira (non-Pro), which (I think) has 15 Hz, but unlike the Dasung, it also a “presentation mode” with more bits per pixel (I don’t know how many, I think it has 12) but much lower refresh rate (feels like 5 Hz). That mode is good for anything that doesn’t move, like reading papers or non-animated webpages.

I am using the Dasung for work, and the Boox for spare time stuff. Typing works better on the Dasung screen, because of its higher refresh rate. Reading works better on the Boox, because of its higher bit-depth.

If I wouldn’t already have the Boox Mira, I think I would buy the Modos screen for basically the same use-case. I am actually considering getting the Modos devkit, and modding my laptop with it, but will probably not do that because I barely use my laptop nowadays and can always just connect the Boox display via HDMI.