It runs Android. It's a Chinese company and comes with a bunch of pre-installed apps, but I just blocked its abilities to phone home and use Koreader. It's been great for me
https://goodereader.com/blog/product/onyx-boox-go-7-bw "The Onyx Boox Go 7 is a dedicated e-book reader with a black and white e-paper display. This device has the same specifications and software as the Go 7 Color Gen 2, except that this model doesn’t have a Kaleido 3; instead, it uses the latest generation Carta 1300 e-paper panel, which increases responsiveness. The key selling points of this model are the physical page-turn buttons and Google Android 13, as well as full access to the Play Store. For those of you who want an e-reader that doesn’t lock you into a specific ecosystem, this deserves a look."
(slower by 2 minutes...)
Yes, I have - I have a Kobo Libra 2 (BW), Boox Go 7 II (Color - same screen as color Kobos) and Boox Note Air 3 (Color).
The issue isn't crispness really - when rendering B&W content the crispness is about the same. However, there's a massive issue with contrast - the Color screen background is very dark and they're basically unusable (for me) without driving them constantly at 80-100% backlight (even during the day). Even at 100% backlight, the page background is darker than the BW reader at like 30% backlight.
This makes the reader eat more battery while being less pleasant for text reading. Moreover, in dark mode (light text on black background) the color screens all show severe ghosting artifacts which don't appear as much on BW screens.
Having said that - reading comics and color books (e.g. programming books) looks great on the color screens. There's just something about that slightly less vibrant "papery" look that's very attractive.
Unless you're a real contrast freak, I think most people would be slightly happier with the color than the B&W; but it's definitely not worth paying extra for.
The C is sharper but the L looks more like a real book/paper. I believe as an artifact of the colour screen and it’s called “screenshot effect”. In the end, once you use either for 10 minutes it becomes “the new normal”.