The house is big, exactly as described. There are a lot of beds (2 double beds per room), so it's an ideal place for large groups. We were only 5 people, so we decided to rearrange the spaces to have a small common area. There is a huge terrace on the rooftop, which I imagine can be very nice during good weather months.
The house is also very well located, really close to Ueno park, Hongo Sanchome, Akihabara, etc. There are several train stations within walking distance.
The only downside for us was the internet connection. There was a pocket wi-fi, but the connection speed was very low and wasn't enough for our work and making video-calls.
Other than that, the hosts are very kind, and replied to quickly to all our messages. They even allow us to leave our luggage at their place before the check-in time. I would totally recommend this place for large groups or long-term stays in tokyo.