I've used AirBnB twice and have had only good experiences with the rental. I think it's important to read the comments because I see a lot of questionable rentals and more often than not the true story is in what the previous renters are saying. I also like to deal with landlords who are upfront with information specially regarding cleaning, extra people, etc. so there are no surprise fees upon arrival.

It's a good concept but I think they need to thoroughly filter the listings.