It's a nice hotel - we spent one night there August 2021 because we got in very late, with all the rental car counters closed, and waited until the next morning to rent our car and drive into Reykjavik. A cab from here to the center will cost you around $200. As JCT001 points out above, even the five minute drive to and from the airport will cost you $25. We had a cabbie, on arrival, who was irked we were just going to the Courtyard and not to the center, as he wasn't getting the full fare he wanted. He asked why we didn't just take the shuttle (there wasn't one at the time due to COVID - I am unsure if this has changed).

Hotel is nice, the breakfast was good. There is not too much in the immediate area. If you do have a car and Fagradalsfjall is erupting, it is not far from the airport/hotel (we saw it in the distance as we checked in late at night, which was a rather cool welcome to Iceland).