Took it
I personally don't have a preference, I see the good in both. I think an e-book would be awesome especially if it was significantly cheaper than a regular textbook. I am also one that likes to highlight, flag, etc but you could easily do that with an electronic version as well---you could print out the page/pages and highlight what you need. I think that would work better because you'd have easier access to the highlighted portion.
But I know that I can only look at the computer for a while before getting eye strain and headaches. I think that would be the case with e-books. I've never used Kindle or anything so I can't really comment on it.