Barbara's flat is lovely, very spacious and clean, with air conditioning (essential for the summer).
The location is great, it is outside the city centre so it is quiet, but not too far away, as it is about 5 minutes to the underground. We were able to get from the flat to the city centre in 15-20 minutes most days. It is also a two minute walk from a supermarket, which was great since we didn't want to eat out for every meal.
Barbara as a host is great, she met us outside the flat and showed us around, as well as giving us directions on how to get from the airport to her flat in advance. She also left a folder of things to do in the city which was useful.