This was our first experience of Airbnb and it exceeded expectations. Our host met us on time at the address and provided us with an overview of the accommodation and how everything worked. He then gave us a good overview of how public transport functioned in Barcelona and tips on how to avoid unnecessary transport costs.
We were 4 Australians traveling together and our host spoke perfect English -bonus.
Don't expect 4 star accommodation because you are not paying for it. The place is clean and homely, there is a great range of tapas bars within 10 minutes walk where prices are aimed at the locals, not tourist, yet it is only a 15-20 minute walk to where all the action is. We enjoyed ourselves.