TL:DR
Pros -
Elevator
All of the toilets
Surrounded by convinis and delicious restaurants
Cons -
Nearest station is Seibu line, so it may be a problem if you're using the JR rail pass
Not really a good group gathering area
Details
First things first. It is nearly impossible to run out of toilets here. That is amazing. The elevator is great for moving luggage.
The neighborhood is charming, with lots of transport options, especially for Shinjuku or Nakano. There's a yakitori place nearby that was absolutely tops.
The kitchen is a bit small, but functional.