What do you think? Is this crazy talk?
Nope, I don't think it's crazy talk at all - I've heard of many people doing it this way. Strictly by the numbers, it would actually be very comparable to a Whitney day hike (at lower elevation, of course). Going down the South Kaibab Trail is about 7 miles, and it's 14 miles up the North Kaibab - and about 5500 ft of elevation gain. Total of 21 miles, 5500 ft of gain, and the overall lower elevation should make it a fair bit easier than a Whitney day hike.
That being said, I think it would be a good idea to consider spending a night at the bottom if your schedule allows. We took our time on our trip, and I still wished we had a couple extra nights to play with. When we got to the bottom and started talking to other people, we learned about some really beautiful day hikes from the Phantom Ranch area that I would have liked to have done.
