The Good:
I start with a few good things: First, the breakfast is decent. There's a wide choice of Asian and European food, and they even change some of the food offered on a daily basis. The huge breakfast room always seems a bit spooky, though, because no matter if you go there at 7 PM or 9 PM, it seems very empty. Unless you stumble over one of the big tourgroups, which seem the the only ones still using this hotel. Second nice point: Most of the hotel staff was actually very friendly and tried to be helpful. Some of them were excellent. I pitied them a bit for having to work in such a badly managed hotel.
Given the fact that most high class hotels in Southeas Asia use tons of insect repellent spray in their rooms, you can, if you want, also see the following as a positive point: Apparently, the Don Chan does not - there were mosquitoes and insects everywhere. At breakfast, in the rooms, in the elevater. Hoardes of them. If this is a "good" thing, depends on your taste, but it gets worse from here.
The Bad:
The rooms all look dated and faded. You can see that when it was built 6 years ago, it was meant to be "classy", but it is no longer. Carpets look worn and dusty, bathrooms are in bad shape, if you look at the details. The ceiling of the pool is a disgrace. Its rusty, lights are falling out of their holes, etc. I could go on, but the impression is the same on all levels.
One short comment on the pool: I hate it that most pools in sunny Southeast Asia are heated until you feel like swimming in a bathtub. Don Chan's pool is not. Which is, unfortunately, NOT a good thing. It's so freezing could that I could only swim a dozen rounds before my fingers went numb. The pool on the 3rd floor (semi-open) has the charme of a parking lot, and is constantly in the shadow. Maybe you get a glimpse of light at 7 PM, but I did not try a second time.
The "view on the Mekong" sounds nice, but in dry season is mainly a view on a huge sandbank. Worse: A sandbank where there's lots of construction going on. You basically have noise through the whole day, starting from 7 PM until late. Noise here means constantly beeping sounds and humming motors. If you stay at this hotel (for whatever reasons I cannot think of), take the (cheaper) rooms with city-view. Much more interesting and a bit quieter. At least during the day. (See below).
The Ugly:
All of the above are only minor flaws to the fact that you cannot even get decent sleep in this place. What I never, ever experienced in a hotel which calls itself "5 stars", is an adjacent night-club with loud music until 3.30 AM. The problem is not the music. The problem is the bass line, that shakes the whole, huge building. After complaining the first night, they moved us to the right wing, promising never to have heard any complains from there. This was wrong, and I am sure they knew it: It frankly does not matter at all where you are: ground floor, 13th floor, right, left... because the ear-wrecking, body-shaking, deep, bumping sound travels through the whole building. It only stops at 3:30 AM, and at 7 AM, the machines from the river take over with bump-bump and beep-beep (see above).
I live in a big city and I am used to street noise at night. I am also used to party music, when my neighbours decide to throw a party. But it's certainly not what you pay this kind of money in a so-called 5-star-hotel.
Don't go there. Unless you want to experience a nightmare about which you can talk to your grandchildren.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC