Looks like I was wrong. Someone found NAP passable but OAP not.
http://www.summitpost.org/phpBB3/viewtopic.php?t=67704If you're acclimated, Dana is very easy, probably the easiest 13er you'll ever do.
Under the same snow conditions, I don't see any difference from New to Old Army. I only find New Army safer under dry conditions because the trail isn't washed out, but that's just my opinion.
The further Northeast you head on Langley, the more technical it will get. You should not encounter anything harder than Class 3 for a few short sections, if that. There is no preferred way up there. Even in the Summer, there are so many use trails...pick what feels best for you.
Depending on your provider, there may be cell coverage. I could not call but could text.
