Opinions of the Advocates General are not ordinarily meant to thrill. Of the thousands delivered over decades, few stand out beyond the core readership when delivered, and even fewer stand out over longer periods of time. The Opinion at hand, however, is an exciting one.
Not only was the adopted legal bases of the EU Minimum Wage Directive incorrect: the EU does not have the competence to adopt such legislation at all, given the overarching objective of regulating 'pay', which Article 153(5) TFEU excludes.