I will also weigh in on the boot side, if you don't trail run. As a runner, I would love to have the comfort of my Asics for the hike up Whitney, but in my three times up Whitney it's been boots everytime. Here's why. I can't tell you how many times on the trail I end up kicking a rock! Whether it is not picking your feet up enough at the trailside meadow steps, or being just plain tired on the way down, kicking a rock in a boot is a bit more comfortable than in a running shoe. I did the hike last year in just over 9 hours, and actually jogged a bit at the end, but would not have traded the protection of my toes for lighter shoes.
Good luck on your upcoming hike!