I visited Philly with my 85-year-old mother, who is still mobile, but not up for a long walking tour. This was an excellent way for us to get an overview of the key sites of Philadelphia without wearing out my mom.
Lois, our tour guide, was just excellent. Very friendly and accommodating and mindful of safety. She made sure my mom was comfortable and able to hear what she had to say.
I always feel like a visit to a town is more interesting when you get to meet a "local" and hear about day-to-day life there. Lois is a lifelong resident and has personal stories and "inside insights" about some of the neighborhoods and historic sites. For example, when we toured Elfreth's Alley (a small street of historic homes that are private residences) she pointed out the homes of a few residents she knows personally, and another home that she had had a chance to see inside. The homes aren't open to the public, so she was able to give us a sense of what they were like inside, and what it's like for current residents to live in and maintain these beautiful places.