The location is perfect: full of pubs and bars, 5' from the Slussen tube station, in a walking distance from Gamla Stan.
The house was very clean and tidy.
I could find only two points to consider for anyone interested:
1. The bathroom was very small and its built was quite strange (but this was mentioned in the apartment's description so there was not any kind of trick).
2. The building was considerably old , and the elevator was something out of a Stanley Kubrick's movie :)