If I understand your question correctly, yes, there is much added value without one single doubt in my mind. Viewing on the net, doesn't hold the candle by a long shot, so for me that's not even worth a discussion. Books, even beautifully printed ones, do not either. Now, to show composition and/or content, as a work in progress so to speak, I would say it is okay (net viewing or books). For example, I own a few original Fan Ho prints and also a limited edition book, beautifully printed, "Hong Kong Yesterday". The original prints are so much better, that there is absolutely no contest. The same ones in the book are slightly over-sharpened, the paper is obviously different, color (toning) is a bit off, and, for as beautiful as the images are, they just fall totally flat compared to holding and viewing the original print. In short, viewing on the net, or a book, are limitations we all live with to present, promote, share, work. There is value in that, but it is very limited when compared to an actual print, to a viewer, a collector, whoever.