I hope someone answers this as i too would like to know. I always get the metro which is good i have never had an delays unlike when i lived in London the tube was always delayed.
YES THERE ARE direct busses to/from several spots in Bcn among which Pza Catalunya, AND night busses too! paste http://www.emt-amb.com/...Besos.pdf on your google bar or look up schedules in front of Corte Ingles Pza Catalunya.