This hotel would pass as a 3 star hotel in most cities. While the location is very good in the heart of the upmarket district and most of the staff speak English, the building and rooms are very tired, looking a bit like something from the 1970's.
On the plus side, the rooms are very large, with the basic room holding two beds and a sitting area - much larger than modern hotel rooms. The staff are friendly and competent. The buffet breakfast is acceptable at a 3 star level, but nothing to write home about. The place is kept very clean and the room maid service is good.
The negative side is that this building is very old and it shows in the rooms. The bathrooms, in particular, are very basic and the furniture looks like it has been in the rooms since the 1970's. The other downside is the noise from outside - scooters and traffic noise go 24 hours a day (a band in the adjacent hall started at 6.45AM for a graduation ceremony!), but this is pretty much standard for wherever you are going to stay in Ho Chi Minh City.
All of this would be fine in a 3 star hotel, priced accordingly. You would get clean, comfortable accomodation at a reasonable price. However, calling this a 4 or 5 star hotel is a complete stretch and for USD 115 per night in other Asian cities I can get a genuine 4 star or 5 star hotel (e.g. Bangkok). I have never been to a 5 star hotel that did not have a pool or a gym! I guess the fact that this is a government hotel rated by a government tourist agency helps the star ranking along!
All in all, you get a comfortable stay in a well-located hotel. But come expecting 3 stars, rather than the advertised 5, and accept that you are going to have to pay for the higher rating.