They are doing just the airport.
The US Cities X by aerosoft does not cover the airports, but more the city and downtown buildings. Thats why it would be cool to have the city done as the field is so close to the city skyline that if you have got a nice add-on field such as KSAN, than it would be good to get a decent skyline to along as the defualt is aweful. San Diego is not that big and should not take away frames that much:)
PSP has little skyline and same with Reno:) But all suggestions are good:)