I haven't done R-R-R yet -- but WILL be doing it next year October. (Rim to Rim then Relaxation!)

Interestlingly, Dug -- after quite a bit of research, study, and self reflection, I concluded my start time will also be 6:00 AM (from the North Rim to the South Rim).

Unlike you, I'll be taking the shuttle back to the North Rim after my day hike to the South Rim. (So, instead of "relaxation", I guess it's also a third rim? blush)

I'm really looking forward to doing this at age 67. My plan is to return to Whitney for an encore peformance there at age 70 (first day hike climbed at 59). (And possibly via the MR.)