Best location in town. Guesthouse is located on a residential street just one block south of Laugavegur (the main drag). This is close enough for easy access to the action, but far enough away for peace and quiet. Rate was reasonable (though not cheap) for summertime in Reykjavik.
There isn't any staff to speak of - just the manager (her daughter also helps out). She wasn't always on the premises, of course, but was always available by phone when she was out. She was friendly and helpful and took good care of our room (and even got my rental car back for free after it was towed!).
The rooms are more like apartments than hotel rooms - ours included a fully equipped kitchenette and a washer-dryer. The guesthouse looks slightly beat-up on the outside but the rooms are fine.
Beds were comfortable, furnishings were basic but nice (think IKEA), wireless internet access worked fine, everything was clean and well maintained.