It's definitely a decision where you have to check your own needs - there's no easy answer, but it looks like we have plenty of opinions to go around! :) Most of what my girlfriend and I kept were her knitting books - though she has a few more good solutions for knitting patterns on the iPad now than she did before - and my metalworking books, because ain't no way I'm leaving my Sony next to a hot forge. XD

You do a lot of SCA costuming and the like, correct? So it makes sense that you'd have a lot of things that aren't well-suited to a black and white ereader.