Courses without Syllabi

I have been experimenting with Case Method as the dominant learning method in management education.

Over the years, I have been becoming increasingly aware of what I should have done in the class versus what I did. That lead to more and more engineering on my part before I enter the class. The more and more the Case class gets engineered, the more scope it gives for getting the gaps in my case teaching highlighted. The engineering includes

1. Articulation of competencies that I want to develop in the student using the particular Case. I now do it with as much specificity as possible. 
2. Specifying the 'discussion blocks' (specific issues on which certain amount of class time gets used) in concrete terms including predictions on the positions the students will take and the questioning strategies that I have to adopt.
3. List of alternative and interesting action plans that emerged in previous classes and the ones I invent which I normally project as though they were presented by students in previous classes. 

While these are done from our side, there is usually very little information on what impact these cases  had on students.

For example, if the case generated lot of excitement in the class, the impact can be excitement with very little learning on the part of the students.

If you ask the student to articulate the impact, the impact gets created then and there due to the demands for articulation.

Pre-post behaviour changes can be very costly to measure and with lot of clouding by other factors.

The question based on the title of this posting is: Is there value in Case Method independent of whatever is listed above? Is there value in Case Method however professionally or non-professionally it gets used? If so, what in Case Method creates that impact with enough play for case 'methods'?