I have stayed in 25+ Airbnbs and this was by far my worst experience. I agree with the positives mentioned by others, but still think it's a risky option.
We arrived late, straight from England, and were woken up by the police saying there had been complaints from neighbours and our host telling the police that my family were part of an art project, staying for a month, and not paying. The police asked me for evidence of this in good English, and I showed them our booking. Soon after this, our host said we should leave and find other accomodation and we would be refunded.
She also sent me a message asking me to tell the same lies she had to the police and explained that she'd had a big problem because I had told the truth. She said the police were only interested in prostitution and terrorism. I had noticed signs by the window saying be careful to close the curtains when changing, so the neighbors would not get the wrong idea, and I learned that although the Airbnb is in a quite alternative small area of cafés etc, the wider area is very conservative. I'm not sure if either the neighbors or police would have difficulty with the LGBT community, and I feel for our hosts if this was the cause of the problems.
Also, I booked 2 months ahead, However, extra costs (3rd person, late arrival) which were not all that obvious on Airbnb almost doubled the price we discovered on arrival. The minute we arrived, our host was quite insistent that we have a BBQ for 10 euro. she was referred to as the doorman by our initial contact,
Carolina, the host, appears to live in Italy. The doorman, Giuseppe/Julia told us all the money goes to Italy so there's no problem with tax that the police would be concerned about... It was Juia who suggested the refund and leaving. When we had found a new place, she said the refund was only to be for the nights we did not spend there, having been asked to leave. I usually don't sweat about things like this, but after being questioned by the police, left without somewhere to stay in August in Istanbul with 2 teenagers, and then told that my not lying to the police was the root of the problem, I really started to care. Airbnb were very helpful and offered most of the refund despite the host's refusal.
I'm sure the other reviews here are absolutely true, but our experience was really not a great way to start an otherwise wonderful holiday, including 3 other fantastic Airbnbs