I had a good time staying at Vivian's place. Vivian and her co-host provided amazing hospitality, since the day I booked.
Pros: Room is clean and quiet. Location is super close to Akasaka Sta. (Chiyoda line) and Tameike-Sanno Sta. (Ginza line and Namboku line). You can walk to Tokyo midtown for 10 minutes. No limitation WiFi (Can't carry to outside).
Things to consider: Fridge is very small like hotel. No elevator.
Overall, was happy with my stay and will go the Airbnb route on my next Tokyo trip.