We got to Can Mano late at night but there was still a waiting list of 4-5 groups of people.
Don't be intimidated by this, go inside, buy a beer and sit on the sidewalk till they'll call you. It worth the wait. Even though this is not the best seafood we had in Barcelona it's still very good and the nice atmosphere of a local un-touristic Barcelona restaurant is very nice. The staff was great (much better than their English but it's possible to manage).