I haven't had much to contribute to the forum recently I wish I was spending more time on trains then in front of school work, but hopefully I will get to change that in summer.
In January I had the chance to spend 2 weeks in Vietnam. I was really hoping to ride an overnight train during my time there, but the state airline was offering fares that made it difficult for to plead the case for a rail trip. Walk up domestic airfares the morning of travel were 19 bucks each way. Which made for some very interesting day trips flying out in the morning spending a day in a different region and then returning to Ho Chi Min City.
I did however get a chance to go to the train station in Downtown Saigon. For $0.20 I was able to purchase a platform ticket and roam freely around the "yard" at the southern terminus for Vietnam Railways. There I was able to view the interiors of the various classes. Here are some of the photos.
Entrance Hall and the only door out the tracks.
Main waiting room in the Saigon Railway Station.
Looking toward Hanoi on the platform.
Coach class car.
Sleeping Car. Hard Sleeper class with 6 bunks in each compartment. You could also book a Soft Sleeper with 4 bunks per room. The compartments didn't have a daytime configuration.
A few more pictures of rail related things.
http://stephenmontero.smugmug.com/Trains/Vietnam-Rail/28854887_cmFFg9#!i=2451045543&k=mmnTg3n
The fares were pretty reasonable, but with airfares that low it was hard to make an argument to travel by rail while in Vietnam. I certainly think it would be a nice trip and I wouldn't worry about safety to much at all anywhere in Vietnam or on a long distance train.