CoolP, KORD by far the one with the most traffic, maybe a close second would be KATL & KLAX areas as they get a big mix of traffic. The New York area did not seem as bad as Chicago.

As for language, Some times the French ATC areas of Europe would mix English and French, but I speak French so it was not a mystery. Once you get south of the Med, the communications can be iffy! Poor English and poor radios.

The procedure for close parallel approaches was to silence the TCAS and just use the TCAS display and visual - out the window. KSFO was one of the closest parallel approaches in the system. They would always stagger the planes so you would have a bit more room.

Lou