There are so many compliments for Mandala, and I've personally confirmed that everything there is worth the money.
The rooms are spacious (it's recommended to book an executive room on the 3rd floor or higher) with good amenities. Adding decorative paintings would make it even more impressive. There's an outdoor bathtub, but I think it's not culturally appropriate, and the bamboo slats don't provide adequate shade, so you still need to wear a swimsuit while bathing there.
The reception area is impressively designed, incorporating Muong culture. The breakfast room is spacious and offers a wide variety of choices.
The resort rents bicycles for cycling around the grounds, which is fun, or you can take a leisurely stroll through the different areas. Remember to use the free, open-air hot spring foot bath service.
The hot spring pool is pleasant and clean; I wouldn't dare swim in the cold pool this season.
The highlight is that the resort arranges many experiential activities for guests (because there's nothing else around). In the afternoon, there's a painting and archery workshop for children, followed by a Muong music show at 8 PM, and ending with an incredibly impressive drone formation display. Afterwards, there's even a group movie screening on the lawn :)