We stayed in a nice Japanese style room for 1 night, and 4 of us agreed that this ryokan is superb! The food is fantastic and the building is beautiful. The staff is really nice and helpful. They have 3 public bath and 5 private bath(which may be quite hard to get one). But we got one and really enjoy the time there. Also you can access the 9 public hot springs in the surrounding area as well.
It's a bit hard to get there. We take Shinkansen from Tokyo, then changed to Nagano Dentetsu, and finally we need to take a taxi to go there. But It is a really good and peaceful place to relax, because there were not many tourists there. Overall we all think that it's worth going! :)