I stayed at this unit for a month for work, and I can definitely say there are few places that are as accessible to the rest of Tokyo as this. You will blessed to be so close (9 min walk) to the JR line in Tamachi which circles Tokyo and provides access to Shibuya and Shinjuku to the West, and Ginza, Akihabara and Ueno to the East (along with the Asakusa line which is faster for some locations). Since the location is in the middle, both the East/West are equally accessible - great for tourists on a tight timeline. The Mita line is also a 2 minute walk away and will get you downtown to Tokyo station which acts as a central hub for transportation; which was also convenient for me to get to work everyday. There is a nearby Shiba Park that is nice, and Tokyo Tower is a bit farther. Plenty of places to eat in the area, and a 7/11, grocery store and hairdresser all within a 3 minute walk.
The unit itself was extremely clean and Mathew is very accessible and will follow up promptly if there are any issues. The area is quite quiet and safe so there is no concern when it comes to car traffic and/or noise from nearby neighbors. My only word of warning is that there is a restaurant on the first floor that will be noisy during lunch hour and will open their shutters at 8am every morning. Besides that, I never heard anything from the other tenants living in the hotel, and for the price you can't go wrong with the location and how expensive other options are in Minato-ku - widely known as the most expensive place to live in Tokyo. Would strongly recommend staying here and at Mathew's other units.