I spent three days in London at Gonul's nice and cosy house. Everything was as expected, or even better. Gonul is a lovely host, she immediately makes you feel like home. The place is a fully renovated attached house from early XX century , and the room was very bright and well ventilated, with a bay window facing the quiet street. A very comfortable bed, drawers and a closet will provide you the required place to relax after every busy day in London.
Brixton is also a great neighborhood with multicultural environment, street markets and a lot of restaurants, bars and even clubs to go out and mix with the locals. It's amazingly well linked to central London, where you can get by tube or (which I recommend, as Gonul kindly suggested me) by double decker bus (about 20 minutes to the Houses of Parliament, 5 minutes more to Piccadilly...)
I can only highly recommend you to contact Gonul as a host, she'll make your experience a lot better, with her advices on transportation, about the visits, her generosity at breakfasts, and much more. I will positively repeat.