United Airlines international product is very nice. In the Economy cabin the interiors may be a bit worn, but overall United Airlines international 767-300 fleet is very comfortable.
From personal experience in May: There should be from 8-10 Flight Attendants onboard. If you can pay for the Economy Plus upgrade at check-in for just a bit additional leg room. The service from ORD
is a hot meal, accompanied by a side salad, and bread. A dessert is presented as well. Snacks are offered at various time through out the flight, as are beverage presentations. About 1.5 hours prior to landing a hot breakfast is served. After the meal service, one last beverage presentation is offered.
Dont believe all the rubbish about United Airlines being horrid and what not. United Airlines 767-300 to South America is comfortable, the crews are very pleasant, and you do have the much adored Channel 9!