Our guide packed a lot of information and sights into a relatively brief tour. She brought a book of photos to augment what we could see, and brought her architect's perspective to expand the presentation to buildings related in some way to GCT. I'm very familiar with GCT, and still saw things that I didn't know existed, and got some good background info on things that I did know about. The tour was fully booked, but the size was easily manageable, which means that Untapped Cities is not overbooking its group tours,. as some are prone to do.