Everyone has their own opinions- in mine there are very few USA airports even as good as FRA- and for an international-international transit there is not a single airport in the United States even as close as good as Frankfurt. The whole "clear customs, pick up your luggage, re-checkin, reclear security" concept is competing with India and Vietnam and in league to be the very worst system in the world.

Arrival at JFK, IAD, LAX are three examples of significant flaws in the USA infrastructure investment system.

ORD may be an OK airport- until you have to take the little train or monorail or whatever it is called which seemingly can only be operated in a non-sterile area.

Even the terrible Senator/Business lounge at A26 in FRA Schengen is leagues ahead of the Red Carpet Clubs in almost all cities in the United States.

I actually cannot think of any country with more poorly thought out airports than the United States.