I traveled to this location with a couple of friends. We arrived late, and Haukur was totally fine with it. We missed out on a couple of other activities (and we arrived at the wrong location at first), but the location was very nice.
The location itself is about 10 minutes down a gravel road from Route 1 (the eastern route of 722 down Vatnsdalur). Upon arriving, you approach a few buildings. The biggest building houses the rooms - five in all on split levels. Room 1 is upstairs on the left, next to the restroom. Inside, we found two beds and bunk with sheets and towels for each of us. There are two restrooms in all - one of the top floor, and one downstairs, next to the washing machine (you use the drying cords and racks to dry your clothes). The kitchen is upstairs and comes very well equipped with a sink, stovetop and oven, microwave oven, pots and pans, utensils, and fridge with freezer.
The other guests (Rooms 2-5) were all cool as well, and Louis (from the Netherlands). We shared stories, locations, ideas, etc., and despite arriving very close to the sleep hours, everyone seemed friendly and welcoming. The showers were all hot and the hot tub (at 2am in the midnight sun) was a welcome break from the previous day's adventures.
If you are driving Route 1 in Iceland, this is a good place to stop. If you arrive early enough, I think that Haukur also has a horse tour, so that's a plus as well!