First of all, the location in South Kensington is perfect. The neighborhood has many interesting stores, and there are two supermarkets within walking distance. There's also the added bonus of a wonderful restaurant (The Abingdon) right across the street from the apartment. Highly recommended; make reservations at peak hours. A terrific Museum of Design is within walking distance. Make the trip there; it's worth it.
This basement apartment itself is very "homey". The bed is quite comfortable. The heat works well, and there is plenty of hot water and great water pressure in the shower.
If I had any suggestions, it's that the apartment needs a deep cleaning. It is NOT dirty by any means; it just needs to sparkle more. Also, there are some oddities of organization. We finally found extra toilet paper in a drawer underneath the oven (!). Also found extra towels and wash cloths in a cabinet in the living room.
Our host, Ali, greeted us and was very congenial. His tour of the apartment was quick and cursory, which is largely our fault. Ask questions. Make sure he explains the washer-dryer (which is just one unit) to you!
All in all, we were pleased to stay here, and the price was quite reasonable for the section of town.