The carts themselves are fun, and great way to travel to see the monuments, though be prepared to feel a bit exposed to the other much larger vehicles on the road. You have the benefit of travelling with a small group and getting an almost private tour. One risk of this is you may be more susceptible to getting an unprepared guide. Our guide was more of a driver, and a bit of an erratic one at that. She was certainly very friendly and nice, as was everyone involved, but not truly ready to give an informative tour that cost nearly $300 for 4 people. At least it wasn't quite what we had in mind. Also the radio earbud you are given for listening to the tour may be more difficult to hear than the audio systems you might find in the larger buses or vans. I found myself trying to listen to the interesting information being given my the more established tours that parked nearby. Work out some of those kinks and this will be a much better experience.