As a family of 5 this was perfect for us. The choice for us was a down town hotel or an apartment like this and we could not be happier with our choice. At the cost of maybe 15 minutes more travel you get to live in a lovely area with small shops and a truly British feel. We especially enjoyed having the space of the apartment in the evening when we were tired after a busy day in London. There is no problem fitting a family of 5 (kids 12,10,6) and we did not find the noise from the street disturbing at all, even with open windows.
There is a bakery/coffee shop just across the street and if you like bagels the 1-minute walk before breakfast is a good investment.