It is difficult to pinpoint a single element that made my stay in Barcelona so enjoyable, because everything was simply amazing!
From directing me to the place during the check in (I came to the city during a taxi strike and several roads were inaccessible), to printing me my tickets for the return trip, Andi was at my disposition all the time. Every time there was any kind of problem (not that there were many) he took care to solve it quickly and efficiently, even at times in which he was not even in the city! At the same time he gave me many useful pieces of advice about where to eat, where to wash my clothes, ecc...
You could not ask for a better host in any regard.
One small thing: the room was clean, comfortable and met my expectations well, but the fridge is close to the bed and and can be quite noisy during summer. It was not a problem because I had ear plugs, so bring some ear plugs if noise bothers you a lot :)