We've had a great time in Stockholm, and it was due in no small part to our hosts. The apartment is spacious and light, with a large dining room/kitchen, two bedrooms and a wonderful balcony where you can have a meal in the morning or relax after a long day. The kitchen is fully equipped (the spice selection is amazing!). There's a bus stop just outside the house. Bus comes every 5 minutes or so, and it takes about 10 minutes to get to Slussen, so don't let the distance from city center fool you.
And of course there's a beautiful lake right by the house. We stayed there in late August, so it wasn't especially warm, but warm enough so that you can have a swim in the evening. There's a pier near the house itself, and a small beach no more than 150 meters away with picnic tables and floating walkways.
We enjoyed our time here, and if we ever happen to be in Stockholm again, we know where to stay!