Overall It was great to stay at Zooey's place!
So yes It's true the place is small (but this is something relatively standard in Japan so not a big deal to us), Akasaka is not where everything is happening in Tokyo (this being said it's quiet which is appreciated as well) but overall everything was great.
The check-in/check-out process was perfect and smooth, Zooey is super responsive to all messages/requests and She has had recommendations about what to do in the area (where to shop...). The apartment is next to a Tokyo metro station and close to ANA Intercontinental Hotel, where you can also grab airport limousine back to the Airports.
So we would definitely recommend this place for 1-2 people and to have a nice stay in Tokyo, thanks to a very accommodating host!