Liz was a lovely host, she was very helpful with direction and getting me settled in. The place was nice and clean. Cosy and a place with personality - I like it funny little details. The wifi was a bit unstable at times, but when it was on it worked perfectly (could stream Netflix). The nearest tube-station was closed (which Liz had informed me of prior to booking), but taking the bus was just as easy and less stressful than the tube ;-)
You're quite close to hampstead Heath which is definitely worth a visit - I went running there a couple of times, but you could also just go for a walk or in the summer bring a blanket and do a picnic (for which the apartment is actually well-equipped - plastic cups, thermos and so on)