I was thrilled to see this tour offered on Groupon. We bought two tickets for $15! We called ahead and reserved our spots, but it didn't seem as if a reservation was necessary. We met outside the Visitor's Station and my phone was scanned for the Groupon. No waiting in line at all. The weather was chilly and breezy in mid-October, but as long as you are dressed for the weather, (whether that be hot or cold) you're fine. The church bell rang and the tour began on the minute, so don't be late. We had a female tour guide dressed in the appropriate garb for the time. She was wonderful. Reading the other reviews on tripadvisor, it doesn't seem as if this group has a bad tour guide! She arranged us in the sun instead of the shade since it was chilly and she always stood on a bench or something high. She projected her voice so professionally we could clearly hear her above the helicopter, car horns, street musicians, etc. The walk is an easy one and we stopped at 12 of the 16 stops. You don't go inside any of the buildings, but for each one she would describe what it was, and what was inside, and if it was free, or a donation or a ticket price in case you would want to go back. She shared facts and stories and had you listening on every word. Nothing dragged on and she was very funny. She asked questions so the crowd was involved. We had young children in our group (not my children). The 4 year old had no trouble keeping up and walking and the children just older all seemed very interested in the tour, so they weren't bored. The tour end right at Quincy Market (How nice!) so she ended, answered any questions and sent us on our way to eat lunch! The tour took 1.5 hours. Many of us tipped her as she was an excellent tour guide and she seemed very grateful! She deserved it!