The multitude of hot springs is fantastic, though the early closing hours of the outdoor mixed onsen is disappointing but understandable. Our favorites were the bamboo forest and the area we referred to as "the grotto".
The gender-specific baths are open for longer hours, and still worth your time, but if you're going as a couple, try and get there early to make the most of your time (or stay multiple days)
The English instructions online for getting to the ryokan are somewhat lacking, and we had to translate the Japanese page.
There were lots of food options inside, all paid (except for breakfast, which is included)
Overall, great value considering how close to the city it is.