Regardless of the courage of individual Catholics and any secret diplomacy or secret actions to protect some Jews, Pius XII for whatever reasons did not speak out clearly and publicly to condemn the Nazi regime. Careful analysis to show that in line 32 of this letter on such and such a date he implied that he condemned the Nazis doesn't change the fact that he did not speak
publicly and
clearly.
Was he right to remain silent? After all, Edith Stein was arrested and sent to the gas chambers after the Dutch bishops spoke out? Still, today Pope Benedict is concerned that so many Europeans have abandoned the Church. I wonder how many walked away from a Church that made itself irrelevant by choosing cautious silence in a time of great evil?
As you say, many Catholics
did go to the camps either because they were local leaders or because they did try to prevent evil and protect others.
One of them, Maximilian Mary Kolbe, was possibly someone I would find to be a real pain in the butt.
He founded the the Militia Immaculata, or Army of Mary, to work for conversion of sinners and the enemies of the Catholic Church through the intercession of the Virgin Mary. That kind of activity is generally the work of a real right winger. There are some hints that he may have written anti-Semitic material.
http://en.wikipedia.org/wiki/Maximilian_Kolbe(Let's be honest here. Official Church teachings were at least borderline anti-Semitic until Vatican II.) He was arrested and sent to the camps. There he volunteered to take the place of another man when the Nazis picked out ten men for group punishment. When push came to shove, he laid down his life for another man.
On edit: playing my pain is greater than your pain is a losing proposition because it distracts from the source of the evil and sets us against each other.