I highly recommend Juan and his apartment!
The apartment is very clean, warm and comfortable like home. It takes 15 minutes to walk to the seaside and the Port Olimpic. It's also near the Ciutadella Park and the Triumph Arche. There're plenty of transportations around: buses, metros etc.
Juan is the most hospitable host I've ever met! He's recommended to us lots of places to go and restaurants (I love these restaurants!!) and he's always ready to provide us with more information.
Anyway, I'm happy that after 3 hours searching on Airbnb I had made a choice with which I'm extremely satisfied.