100% recommend staying at this place.
The location is great - after exploring the city, for me and my girlfriend, we found Södermalm to be the place we wanted to spend most time anyway, as it has all the bars, restaurants, parks and shops we'd want to visit anyway. The apartment is located within perfect walking distance of all of this, and so was a superb place to be located.
In terms of the apartment itself, it is beautifully spacious, and wonderfully decorated, making you feel instantly comfortable and at home. Definitely picked up a few interior design tips just from relaxing in space also. Definitely up there among the best places I've stayed.
Finally, the hosts are superb with being responsive to questions, and being accommodating to requests. It was always a pleasure emailing them, and I always felt they put thought and attention into their responses, which meant planning for the trip was made so much more easy. Thank you to Julia for being (again) up there with the best on AirBnB in this department.
So to summarise, if anyone is visiting Stockholm, and you're interested in staying here, I'd give it a 10/10. We'll certainly be seeing if we can stay here if we visit again!