This place is everthing the other reviews say it is. The room is comfortable and nicely equipped with a dresser, table and chairs. Big by London standards, if not by US standards, and the beds are comfy.
What's really great is the location and proximity to pubic transportation -- it really is a 3-5 minute walk to the Underground/Overground station, and a quick ride into the center of the action from there. The fact that Willesden Junction is in Zone 2 saves a bit on your tube fares. I also recommend the bus, a cheap and easy way to sight-see in London (Google maps will give you directions), and there's a stop right at the top of the road.
Tilda is as nice as can be, an interesting conversationalist with experience in the hospitality industry. And her son is a great, great kid.
The neighborhood isn't Knightsbridge and the house isn't Buckingham Palace, but it's safe and quiet and a good illustration of what day-to-day life is like for non-Royal residents. And at the prices Tilda is charging, it's one hell of a bargain. If you're looking for an affordable, quiet place to stay while you see the sights in London, this place is perfect. I'd stay there again in a heartbeat.