I took it last fall, and you do learn a few things. The big thing is, just like others said, don't act like you know it all.
As for the instructors being more experienced, don't count on it. Here in Illinois, in order to be an instructor, all you have to do is:
1. Be at least 18 yrs old.
2. Passed both Basic and Experienced rider safety course.
3. Take a week long Instructor training course.
4. Teach at least 3-4 courses per year.
So the instructor does not "have" to have more experience. This doesn't mean that he/she won't, but there is a chance.
I am currently looking into becoming an instructor, and I have only had about 2yrs/5000 miles of "street" experience.
Anyway, good luck, and let us know if you learn something!