No idea what the niche would be for this as there are already excellent looking e-ink displays which can play video in a pinch. Who's going to go for a shittier looking one just for a higher refresh rate? I don't think many gamers are looking for shitty looking black and white screens.
Fair enough but is that enough to buy a whole different computer with a much worse display? Modern e-ink displays can do probably 10-15 fps on high frame rate which, while not perfect, is probably adequate.
As opposed to buing a separate display for the computer?
I like to think this thing would be nice reading the news while having a breakfast or reading an e-book outside or at the bed, not near my computer. So it makes a lot of sense to build a tablet with this display technology.
Every use case you described is already filled much better IMO by the high fps e-ink tablets like the Boox Tab Ultra. I would not want to do any of those things on the shitty screen shown in this post.
Looks pretty nice device! Even the camera makes a bit sense in the demo they give (though apparently in practice the scanning rarely works). And cheaper to boot as well. I might consider getting this one.
But is the display really better quality? Atleast the DPI is slightly higher at 219 on the Boox Tab Ultra vs 190 on the Daylight. And Boox weighs 70 grams less, and that's the device some reviews call heavy (and some lightweight..).
https://www.trustedreviews.com/reviews/onyx-boox-tab-ultra "Tab Ultra does let you choose between several refresh modes" and https://www.makeuseof.com/onyx-boox-tab-ultra-review/ "The HD preset works fine for casual reading, whereas the balanced mode works better when thumbing through documents or typing. Meanwhile, the fast mode is suggested for general website browsing, and ultrafast is more useful for video playback. "—surely if the display was always fast and working, this fidgeting would be pointless?
So perhaps there is some room for improvement? That being said, some other reviews don't mention it and one says it's faster than typical e-ink display, though that doesn't sound immediately purely praising.
In the end it probably comes to the software: how fast it is, it well it works, how nice it is to use. It seems both have customized the standard Android, so I suppose the difference is in which one has done it better and which one has better custom apps. Per the reviews Boox doesn't fare too well in this aspect. Maybe someone will make a comparative review of the devices.