I really want to like the more recent devices from Boox. The display tech is just about there with their "Super Refresh." It works well enough for most apps where you are scrolling. Problem is that the software is pretty buggy and can become randomly unresponsive to touch input, which can be pretty frustrating. This has been true on the Tab Ultra, the Tab Mini C, and the Palma 2.
Still, Boox tablets are the closest to what I've been looking for: an eInk device with enough flexibility that I can read more than just books on it.
Avoid Boox. Their displays are very fragile and have a reputation for cracking even if you're careful. That happened to my Air 3 C about 3 months after I bought it. I was very careful with it - never traveled with it, only used it at home. One day after charging it I turned it on and the screen was ruined. I contacted Boox about warranty repair and they said it was my fault and I would have to pay $300+ plus shipping both ways to get it fixed. They have a reputation for blaming the customer first. I'll never buy one of their products again.
Still, Boox tablets are the closest to what I've been looking for: an eInk device with enough flexibility that I can read more than just books on it.