It's a nice property, a bit dated but it was good enough for one night and you don't expect 5-star big city modern luxury at Gero as the place is a beautiful little country town and you're there to get away from the crowds, big cities, skyscrapers etc and relax and enjoy the onsens and surroundings.
It's a traditional ryokan with tatami mats and futons. The room had a little smell but there's a deodoriser/humidifier and you can open the windows to let in the wonderful fresh mountain air. Best thing was the Kaisei dinner with Hada beef, there's so many dishes and we couldn't finish it all! Breakfast was great too.
Location wise, it's about 10-15 mins walk from the main train station, easy to find by Google Maps, but they do offer free pick up service by shuttle buses at scheduled times or a taxi, just need to contact them to arrange. It's also about 20-25 mins walk to the Gassho-Mura village which is a nice walk through the Main Street and up the hill and worth the walk up as you get to see the town.
The hotel has a big onsen and so good to relax after a day's walk. Also, around Gero, there are many free footbaths which you can enjoy, the best one is the one next to the river below the main bridge from the train station to the Main Street. The hotel also has a nice garden with koi fishes and a footbath too for you to enjoy as well.
Overall, I would recommend Bosenkan as good value with the dinner and breakfast and onsen included. I would have included photos too.