Congratulations on your hike. A very thorough report.
I recently completed a rim-to-rim dayhike as well (on 10-01-12) starting at South Kaibab trailhead and ending at North Kaibab trailhead. Actually, I hiked from parking at a picnic site to S Kaibab (plus approx .75 miles?) to the North Rim Lodge (plus approx 1.6 to 2 miles depending on signage?). Started at 0240, stopped at 1601. TH to TH was roughly 3 am to 3 pm.
A similarity. I too passed on side trips like Ribbon Falls to focus on the main effort (I did a small amount of wandering next to the river, but not so much). Had to give up the trail to a mule train. Saw much hiking activity during daylight hours.
A difference. Our routes and direction. There is a free shuttle to the S Kaibab trailhead, but the earliest run at the time of my visit was 0530. Thus my parking at a picnic site and walking in so I could start early. I hoped to time my arrival to the hottest part of the canyon (the bottom which had daytime highs of 94 while both rims were at about 74 during my visit) during the coolest part of the day. This worked out well as I got to Phantom Ranch at sunrise.
I too see a three-segment breakdown in the hike. The downhill (first seven miles). I did this in the dark, not much to see, even with full moon. Hiked with headlamp to help with depth perception. As previously noted, the erosion breaks could be a little troublesome for footing. But overall, the trail is in great shape. No water on this section until you get to the river. Took one short break for a snack and then a longer break at Phantom Ranch. The next seven miles were along Bright Angel Creek with a slight uphill. The last seven break away from the creek with the steep climb out the canyon. Took several breaks and longer ones at the water stations along the way. The steep uphill was some work and I found the toughest section to be between "the bridge into the Redwall" and the Supai tunnel. THe trail crossed over to the other side of the canyon at the bridge and was in full sun exposure as I hiked through at 1230. The sun exposure here really sapped me and there was zero shade of any value until the tunnel. Took a long break at the water station on the uphill side of the Supai tunnel. From this point to the rim, although the trail is still in overall good condition, I would noted that it has suffered damage from the pack trains and has lots of fine dust powder and "potholes".
I used the same shuttle company to return to my car on the south rim after an overnight at the lodge (although the lodge place books out long in advance, there are plenty of cancellations if you keep your eye on the website and have some flexibility). The shuttle company is very easy to work with. My driver was Bob, and he had much knowledge of the area.
As for my vote to which hike is tougher. Physically, my body found the rim-to-rim hike more difficult as I had more soreness in my body afterwards. I drank 7 liters of liquid on this hike - which is quite a bit more than normal for me. I would also note that I hiked the Grandview Trail out to the Cave of the Domes (I think approx 8 miles, but should probably consult a map) two days earlier as well as several shorter hikes (less than 4 miles round trip) before hand in the forests nearby which could have contributed to my soreness.
Fun hike. Recommend it.
