Here's my opinion on the Dimonds --
In a better world, the Dimonds would be arrested by the State and/or the Church and all their "apostolate" websites/materials taken offline. They would be tried for heresy.
Well, it's the 95% of Trads who believe that non-Catholics can be saved that should be tried for (and convicted of) heresy, not the Dimonds. Only a minority of theologians hold that BoD is
de fide, and they do so mistakenly.
Dimonds do great work against an onslaught of people, including the vast majority of Trads, who don't actually believe in the dogma that there's no salvation outside the Church. If the Dimond Brothers are in error on this point (and I disagree with their calling all articulations of BoD heretical
per se ... even as I disagree that it's
de fide), their error is far less grave than that of these Trads who openly reject EENS, often publicly from the pulpit.
Not to mention that these Trads have absolutely no clue about the actual root error of Vatican II, and that in holding that non-Catholics can be saved, they actually hold the same ecclesiology that's articulated by Vatican II.