"From the wikipedia page: 'Once collectivization takes place, money would be abolished to be replaced with labour notes and workers' salaries would be determined'' - so a central authority would do this, assuming all power? How long would it take to abolish all money? How would labour notes be arranged? By a central authority, thereby offering no different a solution to the previous one."

The workers themselves are the authority, there is no centralised authority needed to do this. The labor notes are arranged by the workers themselves and managed through labor unions of direct democracy. Again it is anarchist, so only those who wish to take part in this form of society will, and those who do not will likely join in with other groups.