The two times I day hiked the MMWT I truly hated that section during the descent. IMHO, it is the hardest section of the mountain.
Speaking of people blowing by people...
A few years ago, there was this guy who we think was a JMT Thru-hiker. We talked to him a bit at the tarns above Guitar Lake. We figured he did about 24 miles this day. He eventually spent the night above us near Hitchcock Lakes. He was still asleep when we passed him at about 2:30 AM on our way to summit at dawn. Eventually, we saw his headlight gaining on us. He passed us like we were standing still just as we reached the start of Mt. Whitney. We figure we had good 45 minute headstart and were cruising at about 2 MPH between Lower Trail Crest and the Smithsonian Hut. It is the most amazing feat of hiking I have ever seen.