As a woman travelling to London on my own, I couldn't have been more satisfied regardind the place I stayed. The appartment was very, very clean. I felt very safe thanks to the 4 doors separating the flat from the street, which 3 of them only opened with keys. The mini-kitchen is a must, as it allows to save money on meals (there is a Sainsburry within a 3 minutes walk).
I have been able to do everything I wanted by foot (30 minutes max) except from the Harry Potter Studio (1h public transport) and the Portobello Road Market (30 minutes of Subway).
Last but not least : the appartment is very quiet, and the mattress is... PERFECT. You will sleep like a baby !
I am totally satisfied with my stay, and I recommand it to everybody !