I can't speak for him but on the smallest (7''?) Kindle reading abstracts is a bit of a pain, reading single column per page is fine but double column is annoying enough I'm considering getting reading glasses or a magnifying glass. (I'm 27) I meant to email amazon to find out if you can dismiss the progress bar because with some pdfs it obscures the bottom line which is annoying as all hell. Still highly recommended.

Edit: 10'' would almost certainly be fine. The zoom doesn't really fix the problems with double column pdfs either.