Hey, Guys!
I'm a PADI IDC Staff Instructor and my husband is a Course Director. Since my own IE in '94, PADI has done major revisions to the IDC twice, the most recent being this year. I believe they were addressing the same concerns you express, and thus revamped/strengthened the IDC.
Since neither of you indicate what level of Instructorship you hold nor how long you have been teaching, I cannot gauge how familiar you are with the IDC/IE per se. So here's a brief overview:
At present the IDC has very specific goals/criteria that the Candidate must pass and minimum scores that must be achieved for teaching confined water, open water, and knowledge development (academics). Although there have been no major changes in scoring criteria since the previous incarnation in the confined & open water teaching sections, knowledge development has been refined to include both traditional mod AND prescriptive teaching.
Watermanship skills are also assessed/scored; the 800 yard mask/fins/snorkel swim has been transferred from the IE to the IDC.
Likewise, IDC Candidates must also pass written exams in Physics, Physiology, GSP&P, etc... similar to those at the IE. Again, minimum scores must be achieved or the IDC Candidate will not earn admittance to the IE.
In addition, there is now a very clear distinction between the part of the IDC that must be completed to achieve AI standing, and the whole IDC that must be completed in order to apply to the IE to become an OWSI. AIs now have an advantage in having already successuflly completed part of the IDC.
The IE has also changed. Prior to this year, if an IE Candidate failed the Academics, they failed EVERYTHING and thus had to retake the entire IE. Although the minimum score required to pass the written exams has not really changed (nor the fact that if you fail the GS&P there is no make-up exam) now if the IE Candidate fails just the Academics, they are allowed to re-write only that part in a subsequent IE. The same is true of the teaching sections.
The Rescue Scenario remains the same in both the IDC/IE as do the requirements for MFA (or equivalent) and passing a physical.
Hope that wasn't too long!
~SubMariner~