Staff were brilliant, we arrived several hours before check in time, intending to leave our bags in the lobby. The helpful lady at the desk gave us a map of Nikko, and was marking local attractions and nearby restaurants on it, telling us opening and closing times, details of buses back to the station. By the time she was done, they'd quickly cleaned out our room and let us in early.
The Turtle Inn was slightly old fashioned, but cosy, comfortable, clean and great value. It's only a small place, the rooms were named after months so I'm guessing there are twelve. I saw criticism of the WiFi in previous reviews, but it was fine on the ground floor.
The best thing about it were the two hot baths. They were shared between 'all' the hotel guests (ie, one between six?), but unlike other Japanese onsen we'd been to, you could mark them as occupied and they weren't gender segregated, so you can share a nice bath with your other half and without strangers. Effectively you're getting a private bath for a fraction of the cost you'd pay in a big hotel!
Be aware that Nikko is a small place and restaurants seem to close early, there are only a couple up at this end of town.