I was able to work with a lot of great people. I learned skills that I feel will be extremely useful even if I don't do instructional design as a career. The pay was also pretty great.
What I wish was different
I was given a lot of freedom to do whatever kind of work I wanted. I really wish that I had been more proactive and taken the freedom to learn more.
Advice
An internship is what you make of it. If you are feeling like it's boring or that you aren't doing anything important, then be proactive and try to work on or learn something that could benefit you or your employer.