"This was a pretty cool stay. It really feels like your at a traditional style Japanese Inn! We did both of the private onsens and they were awesome; One option is a wooden bath and the other is a stone bath, both options have an indoor and outdoor bath. It rained on our visit to the outdoor stone bath and it was a great experience, they supply hats for the rain too if you want.
We also did the breakfast and dinners. You get a lot of food for both, so make sure you're hungry, the food is pretty good though!
When it comes to downsides: I don't know if this is everyone else's experience, but when we arrived we were sat down and asked a bunch of questions about our stay (dinner and onsen reservation details, a survey about our stay, etc..) I understand that they need this info, but it was kind of a lot after our train journey when we just wanted to get in and relax. I sort of feel like it could have just been a single paper in your room to fill out and bring to the front or something. I also don't love being locked into times for things, and here you set your time for breakfast, dinner, and onsens. Again, it makes sense that they do this, and it's not a big problem, just something to note if you're planning on staying here! The only other minor downsides are that the shower head kind of sucked lol (water spraying out practically sideways, making it hard to get in the water), and the AC units were quite loud/annoying."