The trolleys & bus situation is mixed -- the network is pretty dense, but you have to build in extra wait time because you often don't get real-time location updates / arrival estimates. SEPTA has advanced a plan to reduce some bus routes but increase frequency on the popular ones, which I would love given where we live, but a lot of people are up in arms about it and it seems in doubt.

P.S. Do you bike? We moved here last year, and one of the things we put a big premium on was living reasonably close to the Schuylkill River Trail. That puts us about 15 minutes from center city and lets us visit our friends in the almost-burbs (like Manayunk) -- and crucially, it's safe.