Terminal 4 is clean, well laid out and constantly upgrading.... Exactly what an airport should be. If all of the airport is run like terminal 4, Phoenix International is a first class airport indeed!
P.S. The best restaurants and shops are in the huge lobby between the concourses before you go through security... This is why I can't give 5 stars... You never know if you really have time for a real meal. If you are ok with bagels, coffee and bar food, go straight through security and relax.