Well, several hours traveling from a different country and dealing with Immigration in Vietnam, taxi drivers and long waiting lines we finally got to the hotel ( not a hotel: probably a person who owns few apartments on the building and hire a person to "rent" them). We got to the place called reception ( a small room on a dark aisle of the 31st floor). And my wife, two daughters and I hear the scary sentence: "Sorry sir, but we dont have any reservation under your name. Sometimes this happen when people use Expedia.
I calmly showed the girl that Yes, I have booked and paid for a Luxury Beachfront Penthouse. She said that they have no availability on this kind of apartment and proposed me to accommodate us in two small apartments and move us to a two bedroom sea view apartment next day.
As we didn't have any choice at that point ( was about 9 pm with two kids) we accepted, asking to discuss the apartment next day.
So we stayed on two apartments and then moved to the third one on the next day. And she returned 20 US/day.
Well, how it was?
All apartments we visited have a toilet inside the shower. Lets say, not so conventional or convenient;
Two bedroom apartment means one bedroom and another bed on the small living room.
Sea view means that, as you are on the 39th floor, you can see the sea on the side of the building.
Cleaning staff was great, nice and helpful.
Two doors with big lockers should ring the security bell, but nothing happened after all.