One thing I will say to those with a tablet/computer using e-Reader software to judge reading books electronically, is that; the digital e-ink screen in the Kindle is a million times easier to read on (and much better for your eyes) than a backlit LCD.
I have both a 9.7" Android tablet with an IPS screen and a Kindle. Besides the obvious battery life difference the screens are not comparable for reading. The next time you are near an electronics store do your self a favour and go and have a look at a Kindle, and then a tablet, and you will see what I am talking about. I am not advocating electronic over paper, but you shouldn't judge the electronic side without at least taking a look at something that specialises in it.
One thing this thread has done is inspire me to take a look around second hand book stores for pTerry books when I am travelling around. As sad as this sounds, other than a few phone calls to check stock; I have never really been in one. And now, I shall shut down my PC and go into hiding.