In my opinion, the difficulty of the 99 switchbacks is VASTLY overstated. I personally think the most difficult part of the hike is the portion between Mirror Lake and Trail Camp. That section is FAR steeper than the 99 switchbacks. And the many TALL steps (ie 12+ inches) make it all the more difficult. The 99 switchbacks are far less steep, and don’t have so many steps. It’s mostly just walking up a trail. The way I see things, once you get to Trail Camp, the hardest part of the hike is over.