Hmm, I always bought the Kindle editions because physical books are a pain in the ass to read. Before the Kindle, I even resorted to a WinCE device (built-in backlight, easy rotation for any position). Kindle Paperwhite is simply the best reading experience I've ever had in my life.
The fact I could get a paper version doesn't even factor into my decision. Actually, the price rarely factors into the decision, as the difference is usually only a few bucks anyways.
One of the things I hate the most about reading books is holding them up while reading. eReaders have solved this problem for me, and now I am a happy camper!
My biggest problem was always trying to hold a book open with one hand. This was a problem because my hands are large and trying to read a paperback with both hands was sub-optimal, not to mention reading in the bath or whilst lounging.
The fact I could get a paper version doesn't even factor into my decision. Actually, the price rarely factors into the decision, as the difference is usually only a few bucks anyways.