This review is based primarily with my experiences taking the 28X Airport Flyer to/from Pittsburgh Airport and Oakland.
Pros: Convienient and cheapest option for a ride to the Airport.
Cons: takes a long time (1.5hrs) and reliability is sometimes questionable. I've had one bus break down, one bus leave 10 mins early, and the very next bus was very very late.
Also, my main complaint is that they do not have a designated area for luggage on the 28X bus. I understand that these buses weren't made to go to the airport, but maybe they should consider having a designated Airport service bus. There's nowhere to put your suitcase, so it ends up in the walkway or taking up a seat.