Vietnam's two largest cities, Ho Chi Minh and Hanoi, are naturally its most visited. However, they lie at opposite ends of the long country, separated by around 1140 kilometers of air travel, 1600 km by road, and 1700 km on a train. Either way, you trek it, the trip from Ho Chi Minh City to Hanoi, or vice-versa, covers a lot of distance. So what's the best way to get from Ho …