There were 4 of us staying at this place for 4 nights.
A flat was clean, kitchen had everything needed, bathroom was totally fine.
Although it's described as a two-room apartment, a "bedroom" is just tiny, has neither a door nor a window. Would not recommend this place for more than two persons: a couch in a living room was barely suitable for sleeping, just uncomfortable.
A big minus - WiFi didn't work at all. After a couple of calls, owner proposed us to buy an available there "Vodafone Hotspot" access and get a refund for this through Airbnb. That was an ok solution, but we spent a lot of time trying to proceed with the payments for the hotspot access, and it was working only for 4 devices (we chose the laptops), so we couldn't use an internet on the phones. Despite that a big thanks to the owner for a prompt help.
Overall being not fastidious we liked staying here. Neukölln might be not the best neighborhood for exploring German capital (most of its population - immigrants from Turkey), but a flat is just nearby a metro station, so you can quickly reach any spot you want.
Recommended for two guests (but you need to be careful when having a stable internet at home is a "must have" for you).