The devices are conceptually great: just an android tablet with e-ink. The software is kind of low-quality. They're fun to use, and good for reducing eye strain while doing things that you'd typically do on a phone, laptop, or tablet, without limitations.
But... the devices are absolutely the most fragile electronics I've touched in 20 years. I've had two break on me in as many months, babying them and being incredibly careful.
The first one developed a line of stuck pixels within the first week of use. It happened while I was using it, which was surreal to watch. They replaced it, but I had to pay shipping, which wasn't cool.
The second locked up a few days ago. I rebooted it, thinking it'd be OK, but discovered that the capacitive touchscreen was not recognized. I'm not the only one. You can see dozens of people complaining about this here: http://bbs.onyx-international.com/t/boox-note-pro-capacitive.... Now I have to use the pen, which doesn't work everywhere in the interface (e.g. for reading PDFs, it's impossible to turn pages) and the device locks up after ten minutes. So I'll be sending this one back too, because I'm outside of the limits for a full refund. Maybe the third one will last more than a month.
Their design and quality control are horrific. The high price of the device only makes sense from the perspective of them having to replace everyone's device three or four times.
I hope e-ink screen having android devices become commonplace and onyx gets competed out of existence.