Dino is a perfect host. The room and the whole place are exactly as described: small but very clean and welcoming. The flat is just next to Regent's Park, has a great view towards the park and the city itself, so the location is perfect; tube station and lots of bus services are just 5 minutes walking distance from the flat.
Communication with the host has been easy and precise since the reservation request. Dino is happy to have a chat if you'd like to, and is very helpful; he knows a lot of the city and can help with many informations about what to see and even how to reach almost everything, from tourist attractions to parks, markets, etc.
Just remember you're a guest in a private house: show respect for the place and the host.
So, a nice room, clean and very well located, at a reasonable price, with a great host; I'd recommend it to everyone planning to visit London!