I do not think Mahoosuc Notch is the hardest mile. I can think of several steep ups that are more physically demanding. It might be the slowest, but it is not the most physically demanding. I thought it was fun and was a bit sad when it was over. I would rate the climb up Hall after coming down Moody as the hardest I have faced. The problem with Hall if you are SOBO, is that between Bemis and Hall you go over Old Blue, go down 2000', and then over Moody. Moody is a bad down because of the rough trail. A lot depends on the direction you are traveling.