I just completed using Ho Chi Minh City for a visa run to switch to a non-imm B visa. Was pleasantly surprised. Cheap AirAsia flight, cheap hotels, cheap food. The Thai Consulate was almost empty. Dropped off paperwork midmorning and picked up the next afternoon. Only thing to be aware of is that most countries must do visa on arrival to get into Vietnam. There's not much to do in the city but had enough time to get in the War Museum and such. Not a bad 48 hours quick vacation.