Long story short, Kei's place was clean, well furnished, and inviting. I traveled in a group of 3, including myself and we all stayed at Kei's place for a few nights. The room was a tatami mat room and all of us slept on futons. I must point out that the futons Kei provided were MUCH more comfortable compared to some other futons provided at places we stayed at after Kei's. He also provided more cushioned mats if we needed but none of us did.
The location is relatively good depending on your travel plans. The location is a little ways away from certain Tokyo hotspots such as Shibuya or Harajuku but only a 30 minute commute on the local trains. One thing to keep note of though and the reason why I say relatively good is that there is no JR line near Kei's place. This means that if you have a JR pass you'd be less likely to utilize the JR pass's benefits. That aside, Kei's place is very close to some awesome tourist spots such as Sky Tree and Asakusa.
Kei himself was a wonderful host. My group was at a loss for what to eat for our first night in the area and Kei went out of his way to show us around the area. We found some great places like All you can drink bar and a 250 yen bento box shop. Kei also extended a helping hand via Airbnb messaging in case we had any problems even after we left his Airbnb.
tl;dr If I ever found myself needing a place to stay I would definitely consider going back to Kei's.