What can I say, I like maps. Sure, you can hike the A.T. using one of the guidebooks and following the white blazes, but maps -- for me, anyway -- add a lot to the experience. Plus they become much more valuable in an emergency, when the little elevation profile in the guide doesn't really provide a lot of info on how to find the nearest road or house.
The Mapdanna is cool, and I own a couple of them, and it would be interesting to hike the A.T. using it as my only navigation aid. But I'd rather have the regular maps.