Don't hesitate anymore and stay with Jason. He is such a great guy with a very clean and new house where I can assure you will feel very well.
His house is right in the middle of a very picturesque residential place where you can really feel like a local, watch a train school and it's students walking in every morning, buy funky stuff in the very near Don Quijote shop, see a beautiful Shinto Shrine just 3 minutes away, and connect to the whole city by the metro or train stations that are conveniently near.
Jason not only offers a great cozy room but also access to his washer, his spacious kitchen, his great TV Screen, and of course wifi to go! Trust me, this device is really useful while exploring Tokyo, since not everyone talks english and almost any street has its name on it.
I can't say enough good things of Jason and his house. I felt really lucky to be there.