I am speaking from brief experience decades ago + teaching students who become high school teachers.
Assuming preparation time is limited, I would prefer a set curriculum, where someone determines which texts are to be studied, over saddling the individual teachers, who have several classes to prepare, and (for younger teachers, all for the first time).
I say this in the name of creativity and freshness, not to the detriment of individual initiative. My reason is that if you have to spend a large part of your time deciding WHAT to teach, you have less time to think about how it should be approached. When you actually teach the class, you cannot get Nechama or your principal or department chair to substitute for you. If you haven't thought the issues through you have nowhere to hide. Regarding the selection of sources, you can allow others to make the choice for you.
Of course, if you do the job well, students are likely to raise questions that force you to do research on your own, and for that you can't rely on the work of others.
I am not touching the question of intellectual honesty here. I recall being disappointed when it turned out that a brilliant high school teacher of mine was very often doing production numbers on books that were fairly easily available. On the other side, I found it refreshing when David Berger, who seemed to have read everything and digested everything, remarked casually that he knew some parts of the course better than others and that in some cases particular books had a heavy impact on the structure of his lecture.
