If you have some kind of overlay screen you can have both worlds. But I was still under the impression that E-ink was the only option. Today I learnt about transflective screens. I hope they catch on. I would buy it.
It can be used as a PC display, which I'd kill for (figuratively) as long as it's affordable. If it's $200 or more, that's not what I consider affordable.
Since such a screen would be most usable outdoors, I wonder about the setup. I guess if it'd be light and thin enough it could be put on top of the screen in that case? Or would you have a separate stand for it?
I have one and use it outside regularly (e.g. [0]), it's pretty amazing!
There's some open-source tooling[1] for it which can control screen features like brightness/refreshes/rendering modes/... and I've set it up[2] to work with my unprivileged user so that I can bind these features to keys in my Emacs.
With these screens you want to use light themes, and use tooling to improve contrast on websites (a friend wrote a Firefox extension[3] which is amazing for this).