I traveled to Reykjavik with my husband and two children (8 and 6) and this house could not have been more perfect. Don't let the solitude advertised in the listing fool you- this house is located smack in the middle between the harbor and the old city. We walked almost everywhere we wanted to go. The one place that was not walkable was the Laugardalslaug pool, but that was an easy bus trip on the very convenient city bus. We walked to the National Museum, the harbor museums, and two other municipal pools while being able to stay in a quiet and private location. The tourist information office right outside the door was really helpful, there is a convenience/grocery store around the block, and there is a hotdog stand in the adjacent square for an evening snack. While we were unable to any tours outside of Reykjavik due to the horrible weather during our stay, the busses (including the FlyBus for the airport) pick up around the block at the Centerhotel plaza.
Elsa was an amazing host, and quickly answered all our questions before and during our stay. She has a very helpful Visitor's Guide and the house had basic food staples which was greatly appreciated. The house was cozy and warm, and the kitchen had all the utensils we needed to cook 1-2 meals a day.
I would stay in the home again (as a couple or with children) again. My children slept on the sleeper sofa in the living room but given the location of the entyy door to the apartment, and the entry door of the building, I never worried about them leaving the apartment without me knowing it. (Sometimes in hotels we don't like to put them near the entry door for security reasons- my kids can be very curious!).
This is a wonderful vacation spot. Clean, safe, accommodating, and accessible to all the wonderful things Reykjavik has to offer.