This small appartement is located in the heart of Gamla Stan. Almost everything you need is in it (even a hot-plate, a hair dryer and an iron) and it looks renovated. It is generally calm even though there is a pedestrian street before appartement.
The only drawbacks were the noise (reaaallly loud) for the garbage in the morning around 07:00 and the fact of using the cellphone as a key (which can lead to issues when you don't have battery left...
I recommend this place, especially for a single traveler in Stockholm for a few days!