I liked them. SEPTA has 3 types - single ended, doubled end cars built by Kawaski, and rebuilt PCC's (called PCC II). The Kawasakis look to be in really good shape for cars built in the 1980's. The highlight for me was the streetcar tunnel that runs under Market St to City Hall. The tunnel is a 4 track structure with subway tracks in the middle, and at some streetcar stops, you can watch the subway trains roar by. I am sure some hardy souls tried to cross the tracks. In the tunnel, the maximum permitted speed is displayed on the operator console, and it's signalled.
My favourite line is the Norristown High Speed line. It's a fully grade separated line with 3rd rail power, and small high floor cars with onboard fare collection. You have to signal for your stop and at stops you have to press a button to flag apporaching trains. The platforms at some stops are really small too. The name is accurate too. It's quite fast.