Wonderful. We stayed for two nights. The staff were very friendly and attentive. Food was excellent, with breakfasts and dinners served in a private room in one of the buildings. In addition to public indoor and outdoor baths, this ryokan had six family baths, which at the time we stayed were all available without reservation. We liked the semi-outdoor family bath the best. Our room was quite large.
We were driving a rented car, and after walking around town, it was our impression that Yamabiko probably had the easiest access from the highway and most convenient parking. That might not be an issue for someone used to driving in Japan, but for us it was a big plus. I think that accessing some of the other ryokan by car would have been a real challenge for us.