The apartment was really lovely and because it's on the top floor actually has a nice view from the balcony. The kitchen is small but has all you need. There were three different ways to make coffee, though not the typical American drip coffee maker. Also the apartment is apparently in the old town part of Reykjavik, which has pedestrian friendly streets and lots of good restaurants and shops.
The apartment is on the top floor, and has the slopes in the ceiling to prove it. We ran into them a few times. It makes the usable space of the rooms a little less, but I thought it was perfect for two people. Another thing to be aware of is that there are no black out curtains. There are shades in the bedroom which make it less bright, but if you feel that you need total darkness to sleep invest in a decent sleep mask. None of the places we stayed had curtains that made the rooms really dark.
The parking situation isn't a huge concern. They only charge during the day, from 9 to 6 if I remember correctly, and that's when you're more likely to be out exploring.
Overall this was a clean and thoughtfully set up apartment in a great location, and I would definitely stay here again.