The staff was very friendly, friendly, but somewhat older hotel was a bit of a challenge with the summer weather. I was in the very top-most room of the hotel and with no fan or air conditioner, It was very difficult to sleep with the heat. I assume this is quite rare in London, so it may not affect your trip like it did mine.
Also, for people with limited mobility, the narrow staircase and lack of an elevator can be a challenge. That did not affect me personally, but I can imagine for older travelers or people who dislike stairs, it could be a problem.