It may seem pricey, but it is definitely worth it.
For a start, the host was great and met us at the apartment and showed us around. We didn't have to call her for any help but she was very responsive.
The place is rather small, suitable for 2 people max, but very homey and clean, and equipped with all the necessary things, besides a freezer (there is a refrigerator).
The best thing about the apartment is it's location- about 10 minutes walk to Pimlico tube station, and from there it is between 1-4 tube station to anywhere in central London.
It is a great place for a holiday ! I recommend it :)