When you begin to travel distances such as to Asia you cannot look at just one airline, but the alliances of which they are part of. Delta is limited in Asia and alliances. United is part of Star Alliance. The Asian partner is Singapore, whcih can not be beat in service. You can take Singapore to Hong Kong (I think non stop) and also to Indonesia. Even using Singapore you can gain miles in the United FF program. United is not my favorite, but I do use the Star Alliance whenever I can. And Singapore is a great airline.
So, not just the one airline, but the alliance. You will enjoy Hong Kong. I have never beem to Indonesia.