Amazing location in the heart of Gamla Stan. Lots of restaurants near by. Less than five minutes to the Cathedral, the Palace and the Nobel museum. Cobble stone streets, narrow alleys . . . truly European look and feel.
The apartment is an attic apartment, so there are narrow stair to climb. Once in the apartment, the main floor is spacious and it's great to have a large kitchen and attached family room. The upper floor is nice, but has low/angled ceilings. Great to sleep in, but not 'live' in.
Note that the apartment is a five minute walk from the train station. And taxis can't get right to the door either ... so there is some walking required and then stair climbing.
We were there 3 days and each day ventured out to different parts of Stockholm. Many things are walkable (or there are lots of scooters laying around). I recommend taking the ferry to one of the other islands just to get a view of the city from the water.