Great location! There's a whole bunch of awesome looking bars and izakayas on the street but it's still quiet. We only went to Hedgehog when we stayed as we were unsure on how veggie friendly some of the Izakayas were.
Really short walk from Yoyogi on the Yamanote line and about 10 mins to Shinjuku.
The apartment is a pretty standard compact Tokyo apartment size. If you're planning on spending most of your time exploring Tokyo and only using it as a base you'd be fine here.
A lot of people, as well as the host, mention it but do remember it's on 3F with no elevator. You do need to carry your bags up so make sure they're not too heavy ;)