The apartment is very clean, comfortable, and quiet. The location is wonderful for public transportation - both buses and the tube. Plus, near the apartment are several places to eat, grab groceries, and also there is a Daunt Books branch nearby. Hampstead Heath is within walking distance, and so is Primrose Park and Regent Park.
The bed is comfortable, the space is clean, and there is great natural light from the huge french door and transom window. Since I had been traveling in Egypt for two weeks before arriving at the apartment, the washing machine was a great asset. The machine was very straightforward and worked well. For those with mobility issues, be aware that the toilet and shower are down rather steep stairs that could be a problem if climbing stairs are difficult.
Overall, this is a fine place to stay. I would definitely choose this apartment again.