Hey, I've still got some of my dad's old War Department/AMS maps.  Those were good maps.  1:62,500 is a little tough to do detailed land nav off of, but for multi-day trips it's nice to have the equivalent of four 1:24,000 map sheets on one smaller sheet of paper.
HJ 
Scale is critical.  Years ago, we attempted a summit for which the only available map was an aeronautical chart.  I can guarantee that a lot of critical features are not depicted at that scale...