Wow, what a ride! We had Allison as our tour guide and Captain Dan as our driver. They played off each other the whole ride and gave a hilarious account of Pittsburgh's history. There were 6 young kids (maybe 8 years?) on board as well as 6-8 adults, and the talk was much more geared towards the adults (lots of puns and a few racier jokes), but the kids seemed to enjoy the experience just by being on board. If Allison is available I highly recommend her--I know a fair amount about PGH history and I still learned quite a bit on the tour...and my out-of-town friend was not overwhelmed with Yinzer references. They strike a great balance, and Allison earned her tip.
For what it's worth, we went on a weekday morning for the first tour of the day, showed up 15 min early without a reservation, and had no problem getting booked.