Boox is fantastic. I have the Palma and it's been very enjoyable, since it's pocketable and has excellent power management, so despite being android, the battery can last 1-2 weeks.
The firm's support is decidedly sub-par, however, should you encounter issues. I'd advise not splurging on their higher-end (larger) devices on the potential lost investment. Though a 13" screen is quite delish for reading technical articles.
There's also the GPL compliance question.