I just enjoyed a great 2 weeks with Alex. His flat is in an amazing central position in South Kensington, right in the middle of all the trendy stuff and 5 minutes on the tube from most of London's highlights.
The bed is a bunk, as advertised, but it's very comfy. I'm a big6'2" and I slept like a log.
Alex and his wife are accommodating and friendly hosts, I'll definitely return and recommend them as a stay to anyone who wants a fun great value airbnb right in the heart of trendiest London.