Overall, the quality of the City Discovery tour, with Dara as guide, was satisfactory. We were in his group for the 10am, Sept 13 tour of the Vatican Museum, including the Sistine Chapel and St. Peter's Basilica.
For a three-hour tour we had adequate coverage, but still that was a small fraction of what the Museum, with its countless artifacts, offers. It's impossible to see everything. Dara offered a lot of details in his commentary. He just spoke a bit too fast sometimes. When you are inserting yourself through thick crowds, from start to finish of the tour, catching some details of his commentary was not easy. One can't pause too long to appreciate a tapestry or some ancient statue, or look up and marvel at the intricately and lavishly decorated ceilings due to the surging crowds. . . and your own tour group has to continue moving on. The only time when people have about 15 min to pause is at the Sistine Chapel. Being the highlight of that tour, there's reasonable time for visitors to try to absorb the enormity of Michaelangelo's masterpiece.
Perhaps, in terms of really skipping the long lines, that don't seem to end, and gaining a broad overview of the wealth inside the Museums and St. Peter's, the City Discovery tour is worth it.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.