The flat's location is incredibly convenient - about a 2-3 minute walk from the Mornington Crescent tube station. It's in a little side street and area that feels clean and safe. There is a lovely little park right across the apartment. The flat is very small, but that should be evident from the pictures and is absolutely fine (especially for London standards). It has everything you could want and need, including a washing/dryer combo and a laundry rack, which was convenient. There were also shampoos in the bathroom, and the host provided a map/guide of London, a hairdryer, an umbrella and plenty of hangers, which was lovely. The flat itself was fairly clean. Ed also answered all our questions and also provided detailed instructions for the self check-in (and check-out), so that was all really good.
There is, as others have noted, an incredibly strong smell of cigarettes and weed coming from the air vents in the bathroom. It's probably from people in the other flats in the building, so nothing you (or the host) can really do about that. Closing the bathroom door helps a little but yeah, it's overpowering. --- The walls are also incredibly thin which means you will likely wake up if people are entering the building or talking in the hallway. Also, there are wet spots on the ceiling in the main room and the bathroom (I'm assuming from guests who did not ventilate properly after their shower). The window also has practically no insulation, so there will be a draft and you will hear people walking past the building and sirens as if they're right there with you in the room. --- The TV also did not work very well (there is a kind of antenna but about 90% of the channels couldn't get a clear signal and were permanently glitching).
All in all, it's a fine place to stay if you're not sensitive to smells and want to be in a central, conveniant flat.