Hope this review will be seen by those going though O'Hara (for the first time) might save those the nightmare we had:
First time and at total nightmare, Arriving at O'Hara on one airline and transferring to another. Arrived on American transferring to United (or any other airline) There are sections where nothing but American or United are. No bulletin boards of any other airline. One arrives in the American sector and is looking for a United flight information you must find the other airlines section before you can get any information. What ever happened to a bulletin board that lists ALL airlines, also since at O'Hara for example United is in a BLUE sector the bulletin board could show all flight of United in BLUE while may be American in ORANGE or GREY helping travelers to know what sector he/she is looking for. In our case I must thank the policeman or maybe he was a customs officer for telling me it was the BLUE section for United and that I should follow those signs. We made the flight as they closed the door behind us.