AVOID BARCELONA! It is unsafe city! Our car was robbed for over 14000 euros at paid (!) parking. Next we found, that Spanish have a law, making parkings not repsonsible in that case. And the POLICE DID ABSOLUTELY NOTHING to find the robbers and our stuff. They did not even look the recordings in surveillance cameras. No surpise that crime here is a way higher then in other european cities.

If the still look for an apartment at Barcelona, David's one is very nice. It is spacious and greatly located. David himself is kind and friendly.

You should know it is noisy because of heating, water system and neighbors, but later we found it is common for spanish houses.
Windows face the courtyard, as well as restaurant kitchens on the ground floor. So we'd prefer to keep windows closed because of smell. I'm sure, most of the apartments in the center have this disadvantage.