Does anyone know how long it usually takes to transfer thru ORD or JFK on an international flight? I'm thinking of either flying UA or AA thru ORD or JFK and continuing on by LH/BA. Are they all located in the same terminals? Is it easy to transfer from the US carrier to the European carrier? I know the trains at JFK are landside. What about the terminal connection trains at ORD?

Also, which is easier on the way back to the US?