I looked quite carefully at both properties since I'm an entry-level member of both loyalty programmes, and chose the Sheraton for price and the slightly better location. Although the décor at the Sheraton is rather tired and the rooms could do with some refurbishment, it's a well managed property. As others have said, the tiny bathrooms, lack of an in-room safe (although rooms have tent cards warning about pickpockets and other such petty crime in the city), user-unfriendly minibars and depressing views from the rooms overlooking the inner courtyard are all major down-sides, but the Sheraton offers late check-out with endless weekend rates (which also include SEK100 F&B vouchers), and again, the location is excellent for both Gamla Stan and the Arlanda Express. I also had a superb meal in the lobby bar of all places. I'd stay at this property again.