Location was good, close to the beach/sea, just like I wanted.
Alex is a nice guy, and was very attentive when it came to my arrival (I let him wait for an hour!) and he was still waiting for me and made sure I understood everything about the apartment. Appartment was modern, looks very good and is very clean. The room is precisely as in the pictures and has a good system to put your clothes and belongings in. It was very hot though (quite normal in Bcn), as the window opens to a very warm, covered patio. Also, you hear the neighbours at the patio very well, so the sound-proof room does not make a big difference unfortunately. I actually opened the door to the hallway because of this (and airco?! in the hallway?). There is a fan provided, that helps a lot.
Price-quality is very good i think, certainly considering the location (15 min walk max to the beach and clubs).
If you want to have a bit of fun in BCN it is a very good spot, if more calm, I suggest you get more to the suburbs of barcelona.

Gracias Alex, hasta la proxima vez!