We stayed in Arp's room and it was perfect. The apartment is very close to central London and very well connected with all parts of the city (there is a tube station nearby and incredibly many bus lines). We were a bit afraid that the busy street would be noisy but it was just a small background noise of the traffic. Richard was very helpful and, although he was not there personally, he answered our whatsapp messages instantly. Last but not least, I recommend packing slippers with you, because it is obligatory to leave your shoes downstairs at the entrance hall.