If you're in a hurry and using extended parking don't waste trying to park near the walkway to the terminal. That parking is always full. Go straight to the furthest reaches of the parking lot where you can actually find a space and take the shuttle
Use the alternate security checkin on 3 to save time
Pittsburgh is a great place for a lay over as its like a giant mall and retailers aren't allowed to charge a premium at the airport stores
Baggage claim used to be slow but seems to have improved quite a bit