Jay's place is very spacious and bright. There's plenty of space to lay out your suitcase and still walk around. The large private balcony was refreshing. Kitchen had everything I needed, the apartment had enough outlets and the mattress was comfortable. The wifi and laundry were lifesavers and the stairs were a fair trade for the privacy and natural light of the 5th floor.
Checking in and out was super easy. Jay has printed laminated instructions inside the apartment about how to use the wifi, laundry and heat. I had an issue with the wifi and he quickly responded and resolved the issue.
The location is ~15 min away from 3 train stations and near everything you need including 2 grocery stores a few min away. Ikebukuru is a little far out from the main tourist stuff, but it's near a lot of anime stuff and shopping and restaurants etc.
The one downside is the bathroom is pretty cramped and smells a little mildewy, but the water pressure was good. There is a mirror outside the bathroom so you can get ready outside the bathroom. Overall I think it was a good deal for the price.