Some interesting background on Vatican II: Diary of an insider (the “insider” was Yves Congar).
I have no knowledge of Congar or his views, but gather that one objection he made to the pre-Vatican II situation was over-centralization. I agree with that. All I’d add is that if centralization is the problem reform-from-above and rule by experts, as exemplified by the New Mass, are not the answer. If coherence is to be maintained, the obvious alternative to bureaucratic command-and-control is greater emphasis on tradition. That’s what all enduring religious communities that lack something like the papacy rely on—the Eastern Orthodox, the Jews and the Muslims, for example.
Another thing I get from the piece is that it’s unclear why there’s more need for me to “believe in” Vatican II than for Cardinal-to-be Congar to “believe in” Pius IX or XII. On strategic and tactical matters, it seems generally admitted, the Church can make catastrophic mistakes.