Nicholas hosted my family (wife and <1 year old kid). As per description and other reviewers, the place has very good access to public transportation and easily connects you to the touristy bits of London. The place we stayed in was large for a small family and also very private. The tiny kitchen area was well stocked, though we only had a microwave dinner on our last night. We also felt that the neighbourhood was quite safe throughout our stay there.
Nicholas was very responsive and warm towards us before and throughout our stay. He fixed any issues without delay - we had a loose towel holder which he fixed it when we left the unit during (with our consent). He also provided good recommendations on the modes of travel to some of the places of interests, which worked out well for us.
We enjoyed our time in London and it was made easier and more comfortable at Nicholas' place. I highly recommend people who are keen on visiting London and exploring Brixton area to Nicholas' place!