It is invaluable if you're using overlaid maps (e.g. with Transdem) to get sharp detail and on a small route (say up to 20 miles) you will probably get away with all 5m grid.
How do you do a map overlay in Transdem? Similar process to overlaying the Tiger lines? I've been thinking it would be amazing if you could take Google maps or Bing maps images and overlay them onto the DEM - it'd make reference work so much easier!!