Well, to start with, the hotel itself is really nice. We had a family room for 7 nights, it was clean and spacious, with a kettle and a bar with drinks and snacks (for a fee). Lots of options you can choose for breakfast, no smoked salmon as someone pointed out in their review, but marinated herring was truly magnificent. SPA is booked separately for a fee from reception. There was some conference held in the hotel during our stay, didn't affect us at all.
Transport. Don't buy transfer to the hotel, unless you arrive in the dead of the night. Arlanda Express or Flixbus will take you to the central station. Best option, especially if you are going to move around a lot, is to download SL app and buy ticket for the duration of your stay. This will give you unlimited access to all that is marked SL (boats, buses, trams, metro and commuter trains). Scan the barcode on your phone when boarding and you're sorted. Public transport is awesome in Stockholm. To get to the hotel, you can walk to Nybroplan (15-18 minutes) and get commuter boat 80, 2nd stop is yours (Saltsjöqvarn), entrance to the hotel is 50 meters away. Or you can get bus route 53 and walk, that is longer and more painful.
Food. Have your lunch and dinner in the centre, there is a giant swarm of restaurants and caffe there. Or, if you feel like a sandwich, there is a Co-op and an ICA supermarket withing walking distance.
Otherwise, the location is quiet and beautiful, people are friendly, we totally enjoyed our stay.