We're planning another rim-to-rim-to-rim in May too! We're probably stopping at the river and doing some day hikes on the way across - exploring Phantom Canyon, and maybe head over to Clear Creek. Hermits to Bright Angel in one day is quite ambitious! Wow! We did a South Kaibab-Tonto-Bright Angel in one day and thought that was ambitious! Just don't do the Grandview-Tonto-South Kaibab without enough water. (Google "Margaret Bradley")