The idea is great, but there are just too many people renting their properties who simply have no idea what they are really doing and how to do it responsibly.
I was receiving answers like 'Sorry, my flat is not available - it is a very short notice" from the renter, who's calendar was 'available' for my dates weeks in advance. From others I heard "This property isn't available, but I will offer you this and that", which were not even comparable. Then I came to the realization to avoid dealing with those who maintain multiple listings, as it's their main trick to lure guests with one available property and then try to market what they have really available.
All in all, there are just too many time wasting opportunities on Airbnb right now. I would rather pay a bit higher to deal with someone definitely reliable and who does it professionally. I think it will take few more years for Airbnb renters to pass the natural selection and earn enough reputation to be easily discoverable among those who rent their flats out to get a payday advance..