I always want my books in paper format, no electronic device I have used compares for straight reading. Having said that, electronic versions are far superior for later reference use (keyword searching alone).
It's why I buy all my SR books twice. Paper at my local game store, and PDF from the publisher. Can't afford that for other games, but SR isn't other games.

If the new novels are available both ways I will buy paper and electronic as well, but the less proprietary the electronic the better. I still remember Beta/VHS, where I chose Beta because it was higher quality, and would not want a reader that went the same way as HD DVD (which I avoided until Blu-ray won for those reasons).
P.S. I have not really tried the hand held readers because the market still seems fractured, is ePub restricted to certain platforms?