[glymor]

The question is how big a hit on reading speed. It's possible to read on anything so that's not a useful criterion.

Personally e-ink is only a small difference off paperback and faster than a hard back. My last LCD was about an hour longer for a book but it had a smaller screen (and the big problem wrt the LCD was a backlight turning off).

Realistically it's things like: how do you turn a page; can you do it with either hand; is it easy to hold. That make more difference.