Went on a South Rim tour with my family in the middle of August.
Pick-up time was prompt. The bus was clean, comfortable and new but nothing extra spectacular. The seats were great, no torn or tattered seats. The bus was non-smoking, the on-board bathroom was of course small but this is expected. It was nice and clean, the most important thing. After a few more pick ups we were on our way. The lunch was a-okay. I was expecting a bland turkey sandwich but this one was really good. I don't eat turkey sandwich but I made an exception on this one! Other than that you might want to get something at the concession store when you get there if you want something more filling. You have 3 hours on the rim, so better plan where you need to go. If you plan to explore the canyon in-depth then this trip is your perfect starter. You'd want to come back and spend a few days here.
However short your time is here, you would not want to miss the visitors center and the spectacular view just behind it! It was so hot when we got there we almost didn't want to leave the airconditioning of the center, but the 4 more extra minutes of walk certainly gave us a view of a lifetime. We would have deeply regretted it if we didn't take that 4-minute walk!
We got back to the strip on time at around 9pm. The tour certainly did not disappoint for 80 bucks!