My family had an acceptable stay here for 5 nights, but I think there are improvements to be had across the board.
The Place : Ok, first of all, it is SMALL. I suppose you should expect a small place in staying in tokyo but our experience here as 3 people was really cramped. With the luggages and foldtable futon bed taking up all the space there is no living or eating area, or even a space to sit apart from the bed.
2 people would make a decent stay here but do note the bed isn't a queen sized one that some may be used to - it looks to be just a super single. And one problem some might note is the place is dim, the lights are yellow and though there are windows you're on the 1st floor so opening the curtains literally opens the entire apartment to a view from the streets.
1 person would actually make the most sense here to be really comfortable but in my opinion, at this price? You should go stay in a capsule hotel instead or any kind of hotel even. It'll be better value for your money.
Cleanliness : It's mostly alright and apart from the furniture starting to show some wear and tear its all okay. But the big problem is the foldable futon bed for the 3rd guest. The bed is placed right on the floor on the foot of the actual bed, with no protective cover or wardrobe area to store. So it'll literally sit there for your entire stays picking up dirt and whatever's on the floor so you're gonna have to put up with that whenever you sleep - which unfortunately triggered an allergic skin reaction for us.
Amenities : The kitchen, washing area and bathroom are all well equipped and the massive variety of soaps and softeners is really a surprise. There is even a drying stand for your clothes, but well you gotta find your own space to open it out. Good luck.
Location : Its about a 10 minute walk from several train stations, with Iidabashi being the only JR Station (if you have a JR pass like us). Iidabashi Metro station is also well connected by 3/4 metro lines - which is great cause its well connected. But also it makes the station bloody huge .... which means from the nearest exit/entrance you might spend up to 10 minutes trying to reach your platform.
The walk to the apartment from Iidabashi station is full of convenience stores and small restaurants which is great, but a small gripe is that there are no 24 hour McDonald's or Starbucks etc so you're in the mood to stay out late after the trains stop running, you really don't have much options there.
ONE major annoyance we had staying here though was the number of warnings and notices (in red large font with graphics no less) all around the flat, about not littering, sorting out rubbish, checking out etc etc. ALL of which included threats of fines.
It makes you feel unwelcome honestly, and it can leave a sour impression. Of course, we have no way of telling the past experiences of the host, good or bad, so I don't wish to make sweeping judgements. But from my previous experience with Airbnbs, usually one or two signs at the door / relevant areas is sufficient and trust and goodwill should tide through from there ..
Long review this turned out to be, but all in all, most of the problems my family encountered here was because we were 3 people, and were really cramped together. As a couple or a solo traveller, this is a decent choice for an Airbnb, if the price is fair across the board. Do check out apartment hotels or even capsule hotels in Tokyo, if you don't mind sharing common areas, those might work out to be better ideas.
Ending note? If you're a party of 3, I think your needs are better met elsewhere.