This is the most reliable car service I have experienced in Pittsburgh. Amazing service. For the last four years, we have used them each week to pick up and drop off colleagues at the airport. They're always waiting by the Hertz counter, ahead of time, without fail. Even when the flight is early or had a 3 hour delay. They charge about $10 more than a yellow cab. If you have client you need picked up or dropped off at the airport, I would highly recommend First Class.
My first time in Pittsburgh, when the driver heard I was on an interview, he even gave me a free tour of a few neighborhoods in the city.