My current bottom line on the judgment is this: It’s basically a ripeness decision (to use American terminology) even if it's cast as a judgment on the merits. The Court acknowledged that, within the CJEU’s sphere of competence, the CJEU had the right to rule on the meaning of OMT in the first instance, as it did in Gauweiler. The German Court, in exercising "ultra vires control," would give some significant deference to the CJEU’s interpretation. But even with this deference, the Court found that the CJEU’s interpretation barely passed muster (indeed, it implied that the CJEU may well have been ultra vires, just not “manifestly” so, per the standard from Honeywell). So, should OMT actually ever be implemented, it will require continued monitoring by German political actors and perhaps even a new ruling by Karlsruhe.
The Court also went to great lengths, moreover, to define the limits and constitutional underpinnings of its otherwise “Europe-friendly” deference--what I called in Power and Legitimacy (pp.166 et seq) "the limits of strong deference." This stands as a counterpoint to the CJEU's doctrine of supremacy. And in advancing this alternative conception of EU law, the Court also strongly rejected the idea that the EU had any normative autonomy apart from what the Member States’ national constitutions permitted. In particular, it is incumbent on all judges (supranational as well national) to police the boundaries of power delegated to the EU level in the interest of preserving democratic and constitutional legitimacy derived from the Member States. In this regard, the Court expressed profound concern about the CJEU's interpretation of the nature and scope of the ECB's independence.
In short, this a very interesting case and one worth of further study and debate. It is also one that may have significant consequences for the future.