This is a luxurious resort. We were the only non-Japanese guests there I think, and we felt welcomed and absolutely blown away by the experience. Our room was like a suite with four beds and a separate bedroom, the amenities were fantastic. The staff were professional, friendly, and welcoming. The breakfast was enough to feed an army and we tried both the Japanese and Western versions. The Onsen was beautiful and relaxing.
Note, this hotel is situated in a hilly area, about 20 minutes drive from the Yumoto train station. Loads of nearby sites including incredible museums, art galleries and restaurants. But if you want to come to sit in your room's private Onsen, you can do that too. You leave your shoes at the hotel front check-in, so walk barefoot or in socks throughout (note for foreigners) and it's lovely. Absolutely safe, clean, quiet, relaxing, luxurious. Highly recommend. And get the breakfast at least once (you might still be full for the next morning so once might be enough).