MoM is a weird ride. It's hard enough, but it really has two big climbs only. One is about 60 miles in, and the last is at the finish. There's some serious steep rollers along the way, but you have a chance to recover. For the last climb, you either have it or you don't, and you don't really know until you're about half way up
I had to walk about half a mile one of the four times I did it. I made it last time, which is when I swore I would never do it again. Ha!