We opted to only tour the lower antelope canyon so I can't say if it's better (or not) than the upper antelope canyon tour. However, even after seeing so many photos of the antelope canyons before our trip, we were still greatly impressed by the sights and magnitude of the place. There are many stair to climb down (and eventually, up) on. In our opinion, despite all the steps, it's not really difficult for an average person -- our 11 y/o, who is mildly afraid of steep stairs and heights, did just fine. You most definitely need to be able to descend down stairs (like metal ladders), and go back many steps up -- there is no other way around it.
We did the first morning tour (in a group of about 25-30people, I believe), and we were at the gate before 8:30a, but the gate opened a little late -- not a huge problem. The tour was about 1 hour, but it went by fairly quickly. Our tour guide (who was also the clerk up front) was very nice, and also offered photo tips, and also volunteered to take photos of us in two areas of the canyon. I positioned myself at the end of the tour line, and I was able to capture many photos (from behind) of a seemingly empty canyon. We didn't see the first tour group in front of us, however, the next tour group behind us did catch up to use towards the end of the tour. Still, I felt that the tours were acceptably spaced out.
And, no bathroom in the canyon, but there are porta-johns outside by the (dirt) parking area. They offer a photographers pass (for free), however, there are certain rules that must be met (slr camera...etc), including having a tripod, which I did not carry with me. Maybe something to keep in mind if it's something you'd like to consider. Overall, it was most definitely worth the money and time. The sight to be seen in the canyon is really beautiful. Great experience!
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