We stayed 3 nights at Savie and David's place and it was a great experience! They are both super friendly and welcoming, and we were lucky to meet them both during our stay.
They let us check in early which was very helpful. The (large!) apartment was clean and we had access to absolutely everything we needed. There's a tube and several bus stations to the city center a few minutes walk from the apartment so even though it's in zone 2, the main attractions are easily accessible with public transports.
Thank you again David and Savie, we would definitely stay with you again if we're back in London!