PhotoReading on the computer is a breeze. Reading on the computer screen is not. That's why I recommend learning on paper based books first.
My iRex accepts, mobipocket which allows me to PhotoRead the text before transferring to the iRex. It also takes in doc, html and pdf files. I can also write my own notes onto pdf files and blank screens.
I also like the fact that I can carry over 600 books in one hand.
Alex