Comparing to the Assault on Mt Mitchell, there's a couple of threads on this. I've ridden Six Gap and the Brasstown Baldbuster mulitple times. I've never done AOMM, but I've ridden up Mt Mitchell from Asheville. (admittedly not from Marion).
IMHO, Brasstown Bald Buster and Six Gap are tougher. Mt Mitchell is just not steep enough to compare to Hogpen or Brasstown.
I think the reason AOMM puts the hurt on people is pacing, going too hard getting to the climbing. Also AOMM gets a mystique buecause Mitchell is the highest point in the Eastern US. I still tihnk BBB, and Six Gap are harder.
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You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.