Whether you play Traveller or Gurps-Traveller, this is an excellent supplement. The details and game ideas are at the level of excellence that we've come to expect from Steve Jackson Games. Players often spend a lot of time at a world's starport, and this helped me to bring them alive in ways I'd never thought of before. The first time your players goto an otherwise mediocre world specifically because they like its starport, you'll know you got your money's worth. Maps of several starports, buildings, and small craft are included. I didn't give it 5 stars only because the book should really be titled Imperial Starports, as it gives less than a page of data on ports outside the Imperium.