I am going for Mount Whitney mid october and I insisted on doing it as a 2-day trek. I think one day on Whitney will bring me to my limits; always good to have som energy left for the end of the day. Before the end of may I am also going to apply for a permit for camping at Bright Angel campground at the bottom of Grand Canyon in the beginning of october. We plan to go down South Kaibab, and up Bright Angel. If we do not get a permit, I think we are perfectly able to do that hike in a day. This is probably also a time of year which is perfect for Grand Canyon, and not so ideal when it comes to cold weather, the chances of snow and ice on Mount Whitney and less daylight. I have never seen Mount Whitney, but been on South Rim a couple of times, so this is just my impression of the two treks from reading about them.
