Steve, I forgot in my last post to comment about what you found about -- the need to reserve WAY in advance for hotel lodging at either the South or North rims. I'd mentioned that earlier in other posts but wanted to remind you of it again.

What is your situation with that right now? What are your plans for lodging at both rims?

Also, John brought up a good point about the temperature. I focused my hike for the fall and through research learned that I would be "safe" in early October. I never fully researched the spring months. You should -- if you haven't already -- authenticate if the likely temperatures (in the canyon) when you will be going will or will not be a show stopper.