I have the Sony eReader. I used to travel quite a bit for work, so it definitely came in handy. I also like using 'ebooks' because they cost a little bit less, they don't take up room in my apartment, and they aren't heavy to move. (And it helps the environment
)
I also like that I can take my reader wherever I go & I use it to store MP3 and pictures too.
I know it has the capability to put PDFs & MS Word documents on it too, but I haven't tried doing that yet
I think the new model that just came out has the highlight/note capability, but I haven't tried that one yet. I have the PRS-505.