Hmm, from personal experience I've seen that while People who don't read regularly see the device, they usually don't grasp the utility of the Device.
However people, who read a lot, either for pleasure or for Work, often appreciate how handy such a device could be.
As for the quality of the eInk, while some people love it on first sight, other may compare it to LCD's. In Such cases, lending it to them for a few Hours / Days has often resulted in them getting used to it and loving the experience.
I ran into the First case with My Lecture who loved it on site, while my Mum was a little hesitent in the beginning. Now she can't leave the house without it
I also lent my Gen3 to my Uncle for a few weeks , who has to read a lot for work, and on getting used to it, asked me to get him one.
So while the mass market might appreciate it, heavy readers can especially appriciate the utility of a dedicated device, and the readability of eInk.