Do not buy any of these:
Or any other device that uses an eInk display.
I am also including this in the Do Not Buy list:
It uses a transflective non-backlit LCD display. But it's no good, either.
I have seen what eBooks could and should be -- and these devices are like an MITS Altair compared to today's computers.
How many of you want to be stuck with that?
These devices are not good for eBooks, they do not represent anything other than a blind and ill-fated attempt to create an eBook market, and the more people buy these, the more they prevent true eBooks from emerging.
Using these devices is a vote for the past. Don't head that way.
Save your money. Save your time. Save the frustration each of these devices will create as you wrestle with them.
You are not missing out on eBooks by not having these.
But those who have sunk their money into these and eBooks for them are at risk of missing out on eBooks.