I have stayed at the room for a whole month and everything was great: the house is very clean and painted in bright colours, the place is quiet, in three minutes you can easily get to a bit more noisy and vibrant Holloway Road, it is easy to get to the centre of the city by the bus or by Tube (night Tube works on Piccadilly. which is nice). Mrs Tong is a very nice and friendly person: when I have locked my key in my room she came pretty quickly to the house to open it. She probably had to spoil her plans to do that. The room itself appeared to be a bit smaller on the photos, so when I came I was quiet happy to find it out.
I am staying in London for two more month, and I definitely had to stay at this room for the whole time. Unfortunately the room doesn't stay vacant for long, so I have to move to another place, but if I need a place to stay in the future I will definitely start by checking if Mrs Tong has some places.