Not who you asked, but personally I'm using an Onyx Boox Palma, which is a phone-sized Android device with an e-ink screen. I have Readwise's Reader on it, which doubles as "read later" and RSS feed reader, and works offline. Pretty happy with the workflow overall - I use it extensively when travelling and having time to waste (e.g. waiting at an airport or while on the plane/train).

Note about Onyx, they're kind of violating GPL by refusing to publish source code. Also, their Android devices are a bit special and you have to jump through a couple of small hoops at set up to be able to use Google Play (nothing special or complicated).