Counterpoint: http://behoovingmoving.com/2016/08/06/superblock-hopscotch-i...:

"The new bollards that will be planted to stop cars cutting through the middle of the superblocks won’t stop that menace of the Mediterranean, the motor scooter rider"

"In Barcelona two out of three streets will be easy to cross, but make a mistake when crossing the third"

I think this is a worthy experiment, but I wouldn't roll it out across the city without knowing whether it will work.

Because to me, the existing blocks simply look too massive to become a truly pedestrian neighborhood, I also would look for ways to cut paths through some of the blocks.