1) Kindle paper white device. Great if my primary purpose is reading. One of the things I really like is it has built-in GSM network that I can use to download books - even sometimes way far away from towns.
Excuse my tech ignorance, but what is a GSM network? I bought a paper white device in 2017 because I got tired of burning batteries using my headlamp to read paper books at night. I absolutely love the thing. As you mentioned, the battery lasts a long time, even with the backlighting at full. The battery also charges very quickly. About the only thing I don't like about it is that you cannot use a book's pages to help start a campfire.
The only time I had to download a book on the road was when I was camping near a small town that had a restaurant offering free WiFi. I had just finished my book the night before and figured I'd take advantage and buy another one. It downloaded super fast.