I did this about 8 years ago, when I was a flight instructor (it was at United training center then). For a flight instructor, it was a incredible look at my future career - almost like a window into what it was going to be like.
Althought the ATOP course is short, it did show me what it would be like when I was hired at an airline and what it would be like. Just being in the UAL training center (back then) was inspiring.
If Wayne Phillips is still the instructor, he is a very dynamic personality and makes it very enjoyable.