This isn't just a hotel, it is a tour as well. We did the single night/2 day tour. The staff put together a great experience. The scenery was beautiful. The cabin itself was ok. It was clean and appointed well enough. But you are going to spend most of your time on the deck looking at the gorgeous views. On the single night, we did three what I would call "events". We had the opportunity to climb one of the islands, go kayaking in an island lagoon, and explore one of the caves. Our guide Nancy was the best!
The only not as great thing was the food. While there were a couple of simply outstanding dishes, the food was catered to a more bland western palate. Which is fine because I'm sure there are a lot of western tourists who complain about spicy food. The food wasn't bad. It was just fine, and I would probably have preferred a more authentic Vietnamese dishes. But then again, I'm a more adventurous eater.
One word of caution: if you have special dietary requirements, be explicit, and let them know well in advance of departure. The food skews toward pork and shellfish, so if you are kosher, you need to be explicit and give them plenty of warning. Because once you are on the boat, it isn't like you can just hope down to the local store.