I like my PEz (e-Ink viziplex), I love the new K4 NT(Pearl E-ink display) I got for my wife's BD.
Now I need to see if I can get her to switch from paperbacks

to the K4.
I failed with getting my sister to take one for her BD.
Both these folk have books in hand

more than once per day

Both use computers daily.
Both have college degrees.
Neither keeps their cell turned on