First post !! Wooohoo
Personnaly, i see Aikido books as good as any other reference book any professional would have in his office's bookshelve, especially the ones about Aikido spirituality/philosophy (i don't believe in learning anything from static pictures, except enjoying the beauty of the art...).
I own several Saito and Saotome Sensei's Jo&Bokken DVDs and I consider these are pure priceless masterpieces. Ever tried practicing 31 jo kata alone in your living room? Having Saito (virtually) doing it with you is a good help when you don't know it perfectly.
Of course this ain't worth nothing if you never stepped on the mat! I consider books and DVDs to be more "collection" pieces for any serious aikido lover. Like good sake and sushis...can't get enough
Anyways, just wanted to break the ice with a first post