What I've seen of E-Paper displays isn't especially encouraging on the cost front, as similarly-sized displays seem to have roughly comparable costs (~US$800 for a 13.3" display). But at least there should be a technologically-independent option, with the prospect for price competition.
During the day it looks and behaves like E-paper, but with a much faster display rate. It’s also got a warm backlight for use at night.
When the backlight is off the contrast is lower than the E-ink Carta panel used in the Remarkable and Boox tablets, but the backlight and fast refresh really help make up for it.
I’m certainly rooting for them. I hope they have more devices available soon
Have you compared sessions where you're principally, say, reading books with a bookreader app vs. Web browsing, or using other apps?
My experience on the BOOX, an E-ink device, is that web browsing (Einkbro) consumes battery at ~10x the hourly rate that reading books (Neoreader) does. How much of that is active display, and how much is other CPU usage, I don't know.
I assume that none of the difference is in active display; the display is static in either case.
The technologies have a similar appearance, but utilise different technologies (electrophoretic vs. liquid crystal). Principle differences are the responsiveness of the display (LCD is far faster) and power consumption (LCD draws constant power, the display clears when voltage potential is removed, electrophoretic displays persist indefinitely when power is off).
As I'd noted in the comment you're replying to, I've used an E-Ink device for years, and am familiar with its power consumption characteristics.
Finding current specs is challenging, but E-Ink Carta, as of 2013 (over a decade ago) was citing a 15:1 contrast ratio:
<https://wiki.mobileread.com/wiki/E_Ink_Carta>
Edit/Update: A more recent HN comment gives 12:1 as applying to most E-Ink displays as of 2020, with 8:1 being more common: <https://news.ycombinator.com/item?id=22832452>
I suspect current displays are somewhat better, and I'm seeing a "50% improvement" comment bandied about but without a corresponding contrast ratio. Earlier displays had an 8:1 ratio.
In practice, displays will have worse contrast with additional layers on top of the display, such as a Wacom tablet, capacitive touch, frontlight, and any surface "tooth" treatment.
E-Paper cites a 30:1 ratio, which would be far greater contrast:
<https://www.newvisiondisplay.com/transflective-lcds/>
I've had direct personal experience with E-Ink, but not with transflective LCD tablet displays.
I suspect that in practice the displays are reasonably comparable in terms of contrast.
I had a keyboard kindle that came with a case that included a dim orange pull-out booklight.
I wish we could still get that. It was much more relaxing to read by than the modern uniform white glow from the page itself.
<https://accessorytosuccess.com/blogs/tools/best-book-light-r...>
Give me an actual booklight where the settings are "on" and "off".
(Bizarrely, the light settings on a Kindle Oasis are barely better - since the light is controlled by an internal menu, as opposed to a hardware control, it can't be operated unless you can see the menu. This means that it isn't possible to have the light off during the day and turn it on when it becomes dark - if it's dark, and the light isn't already on, it can't be turned on. My conclusion is that there are no device manufacturers who understand how or why someone might want to use a lamp.)
I suspect that there are simple, single-colour, single-level clip-on lights.
Or, you know, conventional room lighting / reading lights.
A similar thing happened the tech behind Wacom devices--they enjoyed market dominance, the patent ran out, and now we have super cheap high-precision digital art devices.