I traveled to London for a weekend of operas at the Royal Opera, so Jason's place was perfect for my trip. The location is fantastic - walking distance to most places - and pretty much directly across the street from the Royal Opera House.
Check-in was easy as you pick up the key from a nearby convenience store. My room on the second floor is very nice, and like others have reported, the bathroom across the hall is huge. The entire house exudes old world charm with modern day conveniences. The place is clean and warm and inviting. Coffee and tea are available in the kitchen. Thousands of books in the living room (and bedroom) if you feel like staying in.
Communication with Jason was a breeze. I have messaged him on many occasions and he always wrote back promptly with detailed replies. I did not meet him at the Airbnb; my one interaction was with another couple staying there but only for a minute or two. The rest of the time I felt like I had the entire house to myself.
I am a light sleeper so I always travel with ear plugs. The bedroom faces the main street so there is plenty of street noise (esp on weekends). The room has double-paned windows which keep the noise down but I would still recommend ear plugs if you are sensitive to sound like me.