My wife and I, with our two teenage daugthers, stayed for just about a week, but wished we could stay for longer. The apartment is very bright, practical, clean and has a cozy atmosphere of enlightenment - books of of all sorts and sustainable furnishing. The area is quiet and well maintained.
I would say the location is ideal for experiencing London. Tufnell Park subway station is just a 5 minute walk away, and from there you can get to everywhere in a short amount of time. The area around the station is also nice, with grocery shops (a butcher, a fish shop, a organic vegetable shop and a Sainsbury) and small restaurants (try the pizza from East West).
We also enjoyed beeing within walking distance from Parliament hill/Hamstead Heath park area, and even Highgate cemetery. Communication with host went very well and we would definitely recommend staying here.