Everything was great. My wife and I did not take one single trip by metro or bus. We walked all over Madrid, as the location allowed that.
The apartment is very well decorated and comfy.
The bathroom is small, but that should not count much when choosing an apartment.
The kitchen is well equipped and the living room is comfortable.
Although I have seen reviews complaining about the noise, I confess it did not bother us at all, maybe because we had the heating on, so the outside noise was not a problem.