We stayed here for two nights and had a fantastic experience. Although it’s a bit far from the bus/train station, they provide a free shuttle bus to take you to and from town. Being up the mountain a little ways, the view of the mountain and valley were beautiful.
Another thing my wife liked was that they served both lunch and dinner. There were a two or three hour time frame where you could choose when to have your meals. The meals themselves were Japanese style with many different dishes throughout the courses. By the end of the meals, we were all full.
The rooms were clean and had all types of amenities: TV, wifi, toothbrush, razors, hair dryer, air conditioning/heater, toilet and sink, hot water dispenser, table and floor chairs, balcony with small table, safe box and wardrobe. The only thing missing from the room was a shower. This was fine with us because we spent a lot of time in the hot springs. There were no western style beds in the room. Instead, each night during dinner the housekeeping staff would come make up a floor bed, which was very comfortable for us.
The hot springs were calm and relaxing. They have two private/family hot spring rooms and separate public ones for men and women. Both types have indoor and outdoor baths with views of the mountains. The private baths are on a first come first serve basis, but the room tv shows you if the private baths are available. If not you can wait in the lounge area outside the private baths until they become available. Each of the areas has showering areas with soap, shampoo, lotion...
The staff was extremely helpful and polite throughout our stay. They were courteous and always asked if we needed anything to make our stay better. Also, they were very accommodating if we wanted to change times for meals or shuttle services.
If you ever get a chance to stay in Yufuin, I would suggest choosing Saigakukan. We will definitely be coming back here.