In my opinion, those blocks (known as Cerdá's manzanas) create a much nicer space than normal ones. It also seems safer traffic-wise. True, it takes a bit longer to cross as a pedestrian but I think that's worth the price.
As a Barcelona citizen I can not agree more on your comment. Cerdà blocks are much better than regular square corners, as a pederestian those "dead spaces" are a pleasure to walk, and as a driver makes crossroads much safer.