Andrew's and Gina's place is a gem, and has an amazing location within London. Easy to get there from the airports and most of the tourists attractions are very cloose even on foot. Though Waterloo station is very close so you will have millions of opportunities to choose from any kind of transport to use. Their home is in a quiet little street and it is unbelievable than in a minute walk you can find shops, pubs, restaurants around you.
Their house is very clean, and they are very devoted hosts. Absolutely recommended!