Well I have 3 e-ink devices. My oldest son uses one of them to read over the phone with Grandma.
I have a Nook HD 8gb and a Fire HD7 16gb (rooted).
DD has an HD+ 32gb, and I got her an HD 8gb because I can't have her taking the big one out of the house for any reason.
Other DD has an HD 16gb.
And I just got a second Fire HD7 16gb to give to my boys for Christmas, though I don't know if the older one will use it. If he does, and they both really like using them, one of them can have my rooted Fire.
So that makes 6 tablets, and I set up and maintain all of them. I have a Nook charging station on my dresser.