The best things about the Hotel Regina Wengen" are the staff (excellent) and the incredible views of the Swiss Alps. The hotel is located in Wengen, although the address shows as Lauterbrunnen. This is an issue if you plan on driving because Wengen is a car-free village; you cannot drive to Wengen - you'll need to take the train. (It's an 11 minute train ride and the trains run every 30 minutes.)
The low cleanliness rating is due to a strong smell of urine in the bathroom upon check-in. Otherwise, the cleanliness of the room and property as a whole were excellent.
We ate dinner at the restaurant (ribeye steak) and were disappointed. This is an important consideration because there are a limited number of dining options in Wengen and most close early evening. (The bakery in Wengen is exceptional.)
This is a historic hotel. If you're particular about modern conveniences, the bathroom in the sleeping room could use some updates. Limited space for toiletries, and only a hand wand for a shower. (I prefer a fixed showerhead I can stand under.)
The hotel rooms do not have A/C, so you'll need to sleep with an open window/balcony door to stay cool in the warmer months (we were there in August).
Wengen offers a relaxed stay and offers a good base for those heading up to Jungfraujock. For those traveling by car, consider a stay in Grindelwald or Lauterbrunnen instead. (Once my wife got over having to take the train, she enjoyed our time at the hotel and in Wengen.)