I found that between "I already have it digital", and "I will have it digital once I get to a scanner with a paper-feeder" the distance is too big to my liking. Also it's easier to name/annotate my handwriting (to make it searcheable) right after I finished scribing, then to sort out a whole notebook later. That said, I can imagine a paper-fed scanner to be well enough solution for many people, who already have an easy access to it.