Our host Katarina, contacted me several times to make sure that our arrival went smoothly with good details on how to find the place.
We did not personally meet Katarina but she had someone on standby in case there were any difficulties and she was easily contactable.
The apartment was amazingly situated right in the middle of the old part of Stockholm as described, and very convenient for a lot of the tourist sights. In fact we didnt take public transport at all and found it easy to walk or get a ferry.
It was an easy 15 minute walk from the central station.
The apartment itself was very comfortable light and airy. It had a well equipped kitchen.
I can thoroughly recommend staying there and would return when the opportunity arises.