I would not recommend this trip if you want to spend a long time exploring the canyon and take hikes that descend. It is however an excellent option if you only have one day to see the canyon. The bus was quite comfortable and our tour guide was amazing! She was very polite, spoke with a very pleasant voice and was great at keeping people organized and back on time. The ride is very long, but well worth it. We had about 3 hours to explore the canyon. We were able to comfortably complete the hike around the rim (around 5 km) with my 64 year old mother. We also quickly visited Hoover Dam, but note you only spend 15-20 minutes there.
I also would like to commend the staff for their help, because I forgot my prescription glasses in the bus and they took care of sending them back to my home town in Canada.