I’ve used Airbnb twice without any hassle at all. Once I had a whole apartment to myself, the owner staying at his partner’s place around the corner when rented. This was in a beautiful modern apartment with balcony in Vancouver overlooking the bay which was half the price of the conference hotel 5 minutes walk away.
Another time I stayed in a ‘hosted’ accommodation where the owner was present. I think this is where the experience has the potential to differ greatly – we had a fantastic host, unobtrusive but always there if needed. We shared a beautiful breakfast and interesting chat in the morning, and this is where it really was more of a B&B than just a room in someone’s house (which it can also be). This sort of thing really is’t my usual thing, I’d normally run a mile from such situations. However I was pleasantly surprised at how great it was.