Initially, it wasn't clear how to use the narration feature since the driver didn't point the disposable headphones out to me. Also, the drivers sometimes had their own narrations clashing with the recorded one.
Other than that, the tour was great! I had a good time, learned a lot, and was able to complete the loop the next day (it's a great feature that I'm given 24 hours rather than 1 day to do the tour!)