The flat was perfect : beautiful, clean, quiet, well equiped. It was a pleasure to stay there for 2 nights.
The only little thing concerns the extra bed which is not very confortable for an adult.
It is in the embassy row, not in the city center but there is a bus stop and there are nice neighborhoods around (even a wonderful park / wood to go directly to Georgetown).
Andres and a wife were very kind and helpful when we need.
If I come back in Washington, I will definitely go there !