We stayed at Gerry's for three nights and we truly enjoyed it. The room was spotless, comfortable and cosy; spacious and light. The bed was comfy too! Important, that the bathroom is private, so you don't share it with the hosts - it is indeed like in a decent hotel.
Gerry was a great host. She and her husband were very helpful and simply kind people. Every morning they would bring a tray with croissants and fresh milk up to us; also there were coffee and tea (+ some biscuits!) facilities in the room.
The area, Chiswick, is just lovely, with very easy access to the centre and to the Heathrow Airport. The nearest tube is about 5 mins walk os it really makes no sense to pay much more money for some basement room in a more central area, if in fact you won't save up more time than 10 minutes to get to the main London sites.

I strongly recommend the room which, I am sure I'll rent again when next time in London.