That really highly depends on the person. I actually got the polar opposites during my time in high school. One priest taught junior religion, and he was a bit of an ass. The class got in arguments with him all the time over various things, and he usually came out the worse for wear, resorting to “well, i know better then you, with all my training. Now quiet down.”
On the other hand, my senior religion teacher (who also happened to be the principal), was just generally awesome. Very open minded, highly rational, and just a generally a very smart guy. Treated us like adults, too, which helped. He did a general history of religion with us, and handled topics very well, like opening abortion up to debate in the class, and getting lots of reactions (some quite heated, mine among them unfortunately), and concluded class mostly with saying “It’s a very complex and charged issue”, and let us make up our own minds. When we learned about Islam (keep in mind this was also after 9/11), he gave us a picture of a highly learned and cultured religion (which it was/is). And about the radials, he said “Islam is just going through a hard time, as all religions do. We went through a bad time during the crusades. As Islam is younger, it’s going through it’s bad time now.” And, central to this question, when I asked him about the doctrine of papal infallibility (the doctrine which gives the pope the ability to speak ex cathedra), he told me “Well, actually that was mostly a political move. The church was hoping to combat the surge of nationalism”.
So, yeah. There’s lots of asses, like my first teacher and, i fear, Benedict (can’t say he’s done much I approve of beyond this, which just says “eh, i guess you should try not to die”). But then you have lots of awesome people, like my principal and John Paul II. Just have to take the ones you like and hope the other ones don’t bother you too much.