I've had mostly positive experiences with AirBnB. But it is hit and miss. That's part of the fun seeing what you will get .
One place I stayed in Okinawa, the door was left open, I walked in and there was a big fat shirtless tattooed Japanese yakuza type guy passed out on the couched. I couldn't wake him for 20 minutes. We were standing around him wondering what to do. Finally when he woke up he apologised and got out a broom and started cleaning, then he left. Anyway this place was only for one night when we arrived late in Okinawa and moved on to collect our hire car and drive up to the resort the next day. Was a great start to the holiday and our introduction to Okinawa!