I created an account just to reply here, since the feedback was very helpful. I stumbled upon this site when preparing to do Half Dome. I attempted Whitney 2 years ago and got AMS at around 12.5k feet and had to turn around.

I completely underestimated Half Dome, thinking that if I could make it as far as I did on Whitney I would be ok. Though the elevation gain per mile is very similar, I found Half Dome to be a lot more difficult (elevation aside). The reason being is this:
- The first 3 miles of the Mist Trail are pretty much all uneven steps
- The second 3 miles of the Mist Trail through the Meadows is a steady slow climb through sand
- The ascent to the subdome was incredibly steep

Net-net - the places where there is elevation gain on the Mist Trail to Half Dome are much more compressed, whereas Whitney seemed to be a much more steady climb with not nearly as many uneven steps than Half Dome. To me Whitney was a lot easier. i.e. I'm a lot more comfortable on a treadmill at high incline (Whitney) than I am on a stairmaster (Half Dome).

Note that I didn't summit Whitney, so I don't know what I don't know after 12.5k feet.

It took ~10 hours to summit Half Dome and return which felt reasonably aggressive. Only a few minor stops to refuel and rub out a horrible knot that developed in my quads half way through the subdome ascent.

I plan to revisit Whitney next year and include a few days of acclimation at elevation to hopefully reattempt a summit.

Cheers


Edited by Joel C (10/02/18 01:35 PM)
Edit Reason: grammar