I have made several flights to China and at times paid more to stay with United than I would have paid to fly a competitor. On 9/11/11, I flew for work so that I could be at a new facility first thing in the morning. Since it was 9/11, I figure the less that I carry on, the better. Boy was I wrong. My checked bags hung out in Dulles for 18 hours before making the flight to my destination. The final leg was not a quick turn around and the plane was not that full for the final leg. I was one of about 10 that arrived to find out that their baggage did not. Originally, I was told that my luggage would be delivered by 6:00 pm to my hotel. 6:00 comes and goes and no luggage. I call baggage services and they say it will be 8:00. 8:00 comes and goes and no luggage. I called baggage services again and they say that it will be delivered between 10:00 pm and 1:00 am. I ended up spending 2 nights without any luggage. I wonder why I am putting my loyalty with United!!!!