Our trip didn't start very well as there was some unfortunate misunderstandings with the host regarding what having extra people at the house would cost; however, eventually these were resolved successfully with the help of Airbnb.
It was nice staying at a regular home and the trains to Barcelona were frequent and didn't take long. However, if you like to party please note the trains run until midnight only, except on Fridays and Saturdays when they run until 2am. I would stress though that it really isn't so different from a regular house, as in don't expect anything super fancy; it's a bit worn down in places and there is a strange basement floor under the two main floors that had broken windows and a bolted out metal door. There is a ping pong table outside which was fun.
You are pretty much in the countryside when you go to the house, which is quite amazing considering how close to the centre of Barcelona you are. There were wild boars around which one of my friends was very excited about; she kept hoping we'd see them and one day we did! We didn't find any shops or restaurants in Les Planes itself but nearby Sant Jugat (sp?) which is about three stops on the train is really nice, has lovely cafes and a grocery store.
Overall I'd say I'm happy with our stay, but considering the ample and reasonably-priced accommodation opportunities in Barcelona, I'd say only stay here if you the price is right.