Probably one of the best airports that I have been to. Easy access to and from the airport, not a long drive to downtown and the stadiums on the north shore.
Once inside the airport, wait times to check in for the different airlines are not long at all. All of the concourses are very close to each other and the walking distance between the four concourses is not very great.
The one downside is that the area for security checks is a bit congested and the line can back up at times but with that being said they move you through quickly.
Many options are available for dinning and shopping. There is a great store in concourse B where you can buy anything Pittsburgh sports related.
You can still get direct flights to and from many cities in the US.
All and all this is a great airport.