We stayed 5 nights at Yuka's apt and it was awesome! The apartment was very clean & althogh smaller that i thought, it has everything you need. I didn't meet Yuka but The Zen team responded very quickly when i need them.
This apartment is near the station. Although not at Shinjuku station but its only 2 station away (at hatagaya station). FYI Hatagaya station is not covered by subway pass (i bought subway pass for 1500/3 days) but still have to buy tickets to and from shinjuku to hatagaya for ¥130 / trip.
The portable wifi is so convenience to help you go around Japan. It is not unlimited though, but i got 7gb for 5 nights which is enough for me. There is no TV in the room, but who need TV in Tokyo ;)
The apt is yes near the highway, but I didn't have issue about the noisy sound that some people mentioned. It only become noisy when i open the door.
Afterall it was a good and nice place to stay while you are in Tokyo. Just feel like home :)