We ate dinner here in June 2014.
Atmosphere: was the only restaurant in Iceland we had to wait for a seat- it was packed! Restaurant is right on the harbor, so pleasant views from all the windows. Service was very quick and friendly.
Food: The menu is ala carte and all organic- there are the fish of the day (when we went there were 3 kinds) and you can order the fish in a recommended combination (such as in a salad or in another dish) or you can order them plain (fried) with a choice of nine skyr (a soft cheese that tastes like yogurt)-based dipping sauces. You can pick one sauce, or try 3, 6, or all 9 in sample sizes. We decided to get two different kinds of fish with the 9 size sampler. Our favorite sauces were mango, coriander/lime, and chili/roasted pepper.
Prices: For Icelandic prices, a very reasonable and delicious dinner. Our two servings of fish and all dipping sauces was about $40