My partner and I stayed at No.9 Rathgar for one night. Thankfully it was only for one night, as we were quite disappointed with the room. One thing to be aware of is that the rooms look quite different from the pictures online.
The biggest issue for us was the cleanliness. While the basic things like the bedding and bathroom appeared to have been cleaned, it was clear that the rest of the room had not been properly cleaned in a while. For example, there was a significant amount of dust built up on the bed frame and the table beside the bed. There was so much that I had to wipe it off before I felt comfortable putting anything on the surfaces, and the dust was also making me cough.
The curtain was also slightly coming off, which was noticeable, although it wasn’t a major issue. Unfortunately, the bedding also made my skin feel sensitive and itchy, which was not something we experienced at any of the other hotels we stayed at during our trip.
They do have a lounge area with a microwave and coffee and tea available, which is a nice feature. I am not able to comment on service as they don't have reception. Overall, we were not happy with our stay because of the lack of cleanliness and would not recommend it.