Great value for money and tour guides really good. Great way to see Philadelphia if you have a short stay.
We bought a 2-day pass for Sunday and Monday. On Sunday we waited an hour for a bus in the middle of the day, then finally called Big Bus to learn that it was a holiday and because of a parade the tour was called off. We were never notified by them or Viator.
On Monday we waited an hour at stop 18 before it came at 10:30 am. Their brochure says intervals are 20-30 minutes starting at 9:30.
We had two different buses, each with a different tour guide who spoke in a microphone. Because they both spoke so rapidly and ran their words together, we had trouble understanding them.