Our stay was great!
The location is absolutely wonderful, very close to two underground stations and a 10-minute walk from another.
Our hosts were very, very responsive, took care of any issue we had very quickly and made sure to answer any of our questions immediately, they made us feel very comfortable.
The flat is simple and small, just as you'd expect, but very accomodating, equipped with everything you need and is very cozy and comfortable.
It was quiet around even though we slept with all the windows open (it was really hot in London for a change)
It was spotlessly clean.
All in all I'd rate it a very highly recommended budget stay!