The printed ticket told us to go straight to the coach and show the ticket to the ticket-taker. Unfortunately, the railway personnel at the gate would not let us on to the platform because we did not have an 'official' ticket with a bar code they could scan. And therefore we were told to wait for someone to show up. Someone did eventually show up, with a large tour group and we thought this person was their tour guide as she was not wearing any kind of official uniform and seemed to be talking only to the big group. Only later did we find out that this person worked for Livitrans/Violette and had the power to let us in and tell us our coach and berth numbers. So after much drama and wondering if we will get on the train, we finally did get on it. So the system works, sort of, if you are patient and know what to look for. Livitrans and Violette can make it a lot easier by having thier personnel wear clearly marked clothing so they can be identified. Also, assigning us berth numbers before hand would have helped so we could have planned if our family were to be split up (we were not, but others on our train were).
The train ride was fine. The air conditioner was on pretty strong in the middle of winter and we were given only a thin duvet cover (not the duvet itself). My wife and daughter were very cold at night and I raided the staff's compartment to get more duvet covers for them. Why they cannot provide a blanket that is thick enough to withstand the AC is a mystery to me.
Eat before getting on the train and bring as much food as you can with you. The food on the train is below mediocre. Also bring enough water. The staff on the train is helpful, but speak very little English or any other foreign language - take that into account.
If you traveling between Hue and Danang during the day, the scenery is beautiful. That makes the trouble of the train ride worth it.
Don't let these types of problems deter you from taking the train. They do get resolved eventually - you just have to be mentally prepared to deal with them.