I do not see the books as a philatelic collectible any more than I see stamp catalogs as collectible. However, there can be interesting history with in the books, be they Celebrate the Century, WWII and the like. Those I share with children for the "history" with the child noticing the history is reference on stamps.
Then again, I am interested in collecting a US #2179, the twenty cent Apgar but I am far more interested why Dr. Virginia Apgar showed up on a stamp and most interested in the Apgar score
as the new family additions show up. For me, there is more to stamp collecting, philately, than just the little pieces of paper.
Edit: Regarding interesting stories behins some stamps, see my 16th post on this thread: http://goscf.com/t/81312&whichpage=1#742090
to learn why we have 3D, vinyl record, video CDs and other unusual stamps.