My wife and I just returned home from staying at Karen's place and we can't stop talking about how great a host she is and how wonderful her place is.
First about the house, it was designed by an architect and that shows through in that every detail of the home has been thought out. This is truly an Art House and all of it is lovely and well curated by Karen and her husband. All this is backed up by top quality everything (Kiehl's products in the bath, Henckels flatware, etc.) in the house.
Second about location, the house is on a very quiet street in Dublin's Silicon Docks (about one block from Google's HQ). It is close (< 1 km) to many cafes, restaurants, and public transportation. Trinity and St. Stephen's Green are both about 2 km away, which we thought were very easy to walk to as well.
Finally, about Karen, we have not encountered a better host in all our AirB&B travels. She is everything you want in a host and truly made our stay in Dublin much better than it would have been.