My wife and I visited London and stayed at Phyllis' place for 4 days. We had a fabulous time. The location is supreme - it's within 1 block of Trafalgar square and the National Museum/Portrait Gallery. Related to this, it's within 1-2 blocks of 2 separate Underground lines, a couple of blocks from the river and a short walk to Buckingham Palace. The area is as central to London as you can get. Not surprisingly, there are great restaurants and pubs nearby.
Phyllis is a wonderful host. She communicated with me by text before my arrival, which made connecting with her smooth and easy. She is a charming, delightful hostess who is full of good ideas and great advice. She's also fun just to talk with - over the 4 days my wife and I found ourselves frequently having long, enjoyable chats about art, philosophy, microfinance (she has given a TedX talk on this!!), food, etc. Such a pleasure!
The space itself is small but comfortable. It's in a newly renovated old building with very high ceilings, a broad staircase and a small, classic older European elevator. The bedroom that she rents out has a comfortable queen size bed with two bed tables. The space is tight, but it doesn't feel tight because there is a huge window with a "forest" of potted plants on the fire escape and an entire wall with built in cabinets, drawers and closets, making for a large amount of room to store your stuff and keep the floor clear. There is a bathroom dedicated to the guests across the hallway immediately opposite the bedroom. It is clean and has everything that you need.
The kitchen is small but very efficient. She provides a great assortment of teas (... this is Britain!!), coffee, cereals, breads, yogurts, fruit, milk, etc. She is aware of eating needs and provides gluten free foods. Every morning she put out place settings, which was a nice touch.
So, altogether an A1 choice!!