They are doing construction at PHL, so it has been a mess lately. Probably just slows everything down even more.
I have to say that 80 percent of the time I don't have any problems at PHL Hertz -- as long as my name is on the board it is relatively easy to pick up and go. If your name is not on the board, then problems can begin.
On the return, the bus-ride issue is pain, and takes longer than walking. It is always running late and then takes a tour of the airport before you get to your terminal. I never take the bus at PHL, but walk over the the terminals unless I need to go to Terminal A (which is a long walk!). The walk accross the road can be tricky if there's a lot of traffic, but is always quicker.