The problem with the Web, is that you can find just about anything about anything, and what you find may not be what you were hoping for. For example, I enjoy tormenting (well deserved by the way) a co-worker with links to very graphic videos of the surgeries I have had the past few years. He no longer opens e-mail that have a subject line of “You gotta see this!”.
When I bought my pack the other day, the very nice and knowledgeable person at REI mentioned that the Park Service frowns upon hikers clipping into the cables, so I did a search on that. I found one helpful site which said to definitely clip in, citing all the possible ways you can die if you don’t. Great. Then I found a NPS video clip on hiking Yosemite, which was created I think, to scare the bejeebies out of most people considering the hike.
It did nothing but reinforce my plan to use a harness and clip my way up and down the cable. It is my life after all. I then found a video from a group that did clip into the cable - much safer, especially going down. Built up my confidence after the first video.
https://www.youtube.com/watch?v=LFdA58m-AWw
But Youtube has tons of videos taken on the cable route, thanks to GoPro (I plan to use mine, with a new chest harness that I bought). This last video is probably not the one to watch at all for anyone planning the hike since it describes a woman’s miraculous survival of falling out of the cables, and bouncing down until she hit a vertical rock which kept her from falling the rest of the way to the valley. She had to be rescued via helicopter, in really bad weather.
I watched one more clip from a guy who did a video of going down (his first audible comment other than sounds of hyperventilation was “Holy Sh*t”) - really, really steep, but survivable if you hold on tight. Incredibly steep - it is definitely 5th class on the rock climbing scale, something like the 3rd Flatiron in Boulder which I’ve done a million times. But always climbing up, not down. The two free hanging rappels from the 3rd look much safer than sliding down the steep stretch.

