Well to start, I would absolutely stay here again. We had 5 adults visit the apartment for 4 nights in mid-May, and found the location perfect for a quick London vacation.
The apartment was very easy to find, and the Tesco Express market on the ground floor of the building supplied all of the basics (breakfast, wine, quick microwave dinners, etc). The overground stop is right around the corner (2-minute walk), which made it easy to get to the center of London and switch to the underground to quickly get to all the tourist sites.
We found the apartment exactly as described in the listing, and was very comfortable for 5 adults. The patio was a nice addition, which we took advantage of on several nights when we had mild weather.
Prior to arriving, we had several email interactions with the hosts, which they responded to quickly, which made our arrival and stay a breeze.
I would certainly recommend this for a group of 4 to 6 adults.