Don't eat the whole enchilada. What I mean, is give importance to what's important. During DMC and IDC training, people become obsessed with a lot of things. This is the nature of the beast (*at least with PADI) it's all about passing the IE. The Course Director will emphasize what is needed to pass the IE. Try during your DM and later on parts of the IDC, to not forget that it's also about real teaching, real diving, real learning. If you think I sound harsh, it's because PADI is not only aimed at the lowest common denominator (discussed elsewhere on this boards frequently) only for Basic Open Water. The IDC just reflects that on a "higher scale".
If you find a good Course Director, it will be one that is still in touch with DIVING. And not one only in touch with running IDCs. And trust me, it's not that easy. To become a CD in the first place, you need to drink a lot of PADI kool aid. And to be quite honest, it's tough to not drink it and achieve that rating. So take everything with a grain of salt. Learn the stuff, do the stuff, but use your own brain also. There is a strong "learn by repetition" (of bad things in many occasions) agenda in the way DM and IDCs are run. It's instruction inbreeding (with all the bad mutations and deformities that inbreeding brings). Many people come out of an IDC believing that what their Course Director or staff member (taught by that CD probably) is the one and only truth. There is usually little time during the IDC to make any deviations from the strict must-see to pass the IE curricula.
There is so much more to diving and teaching and standards than what most CDs want everyone to see. They have a business and they will milk it to the end. It's not about making good instructors. It's about passing the IE and cashing in both them and PADI.
Good luck, and think outside of the box.