The amenities exceeded expectations. The room was larger than expected. We had a four futon room with three futons setup. It would have been a bit tight with four. The room had a living area, a sleeping area, a garden viewing area, and a balcony. We did not opt for the private bathroom. We may have stayed during a slow night (Early Jan) because we still had the shared public bath to ourselves after dinner, and we enjoyed a nice soak. I saw an older review saying there are no hair dryers. They have hair dryers now.
The dinner and breakfast was good as well. If you're not used to Japanese vegetarian dishes, you might find the food lacking. It's a lot of radishes, bamboo shoots, seaweed/kelp, tofu, squash, rice, and mochi. Most of it is served cold with unlimited warm rice and hot tea. I thought it was quite good.
The morning ceremony was a great experience. The monks will encourage you to do the incense offering. A booklet in your room will explain what to do. Read and research beforehand as it's not explained during the ceremony.
Overall, I'm glad we stayed here. It was a good experience. I did not get to interact with the monks. I wish I was able to do this to learn more about Koyasan; however, I understand most of them do not speak English.