The Sofo is really close to everything thanks to being just one major block from the T-bana at Skanstull. It also has access to the bus lines which will take you up to Slussen and you can then transfer to pretty much anywhere.
The hotel itself is located in the basement of a building off a quiet side street. It uses a coded entry and the door is always locked. Which is nice because you don't have to worry about people coming in and out who aren't staying at the hotel. Once inside, you do have to walk down steps to enter, so if you are unable to do that, or navigate with your luggage, that is something to consider.
The lobby is also where you have morning frukost (breakfast). And I have to tell you it's delicious. They have a fantastic amount of food they put out. You should be able to find something to eat. I was amazed for the price of what I paid that the breakfast was so generous.
The check-in desk is just in the hallway, once you get your key just head to your room. Mine was just across the hall almost. My room was ample for one person, with a great bathroom. They clean your room daily. Also amazing for the price paid.
My only complaint is that the room door is a little thin, so any noise in the hallway you could hear quite loudly. However, I solved that with a pair of earplugs and not a problem. Otherwise. Had a really great sleep, great room.