Overall the flat was cosey and in a quiet location, with central London. And I certainly would have given it four stars , however, there was quite a lot of internal in noise, from the flat about - footsteps on a hard floor are very loud. And the bed squeaked loudly every time I moved. The pillows were far too thin and not really very comfy. Generally I would think that given pillows are a small expense BnB's could always provide good quality comfy pillows, which they generally do in our experience.
Location is excellent.