The apartment was well located close to many restaurants and public transportation. The building had security and a reception 24/7.
Some of the cons: we did not meet Helen, and nobody welcomed us when we arrived. Some of the lights in the apartment were not working and the extra bed in the living room was really uncomfortable. We run out of towels since we stayed for 5 days.

The apartment was kind of pricy for the condition it was.
On the other hand, we had an awesome time in London and Helen was truly nice !