Trip to Asia

I have an exciting trip to east Asia planned for this August.  I am flying from Boston to San Francisco to visit friends there, then to Bangkok, Angkor Wat, Phnom Penh, Saigon, Hanoi, Beijing, Xi'an, Shanghai, and finally home to Boston.  Orientation for my graduate school program starts on August 24; my plane lands in Boston at 1:30 pm on Aug. 23.

I plan to spend about two non-travel days in each city in Thailand, Cambodia, and Vietnam, and then about three or four non-travel days in cities in China.  In Cambodia, I will follow the typical tourist route of visiting the temples at Angkor Wat; in Vietnam, I am deciding between the train from Saigon to Hanoi and the plane.  The plane is pricier and faster, while the train affords better scenery and costs less.