Hi, we are travelling to Sapa mid September with 2 adults and 3 children. This poses an issue when it comes to booking a cabin on the train. It becomes very expensive. Train is definately the way we want to travel there. We have been suggested the 6 berth hard sleeper cabin. Just would like to know if anyone could tell us how different the 2 types of cabins are. Also how secure a 6 berth is in comparison to the 4 berth.