Pros
As the leading research organization in the area of industry standards and career strategies in the motion picture industry, MPii is by design the best place to do some of your first internships, because the focus is on high-quality, career-vital training.
Cons
As an all-volunteer, nonprofit industry organization that for 30+ years has been mainly focussed on providing research and career-building support for mid-career working professionals, at MPii you have to be a self-motivated, self-starter. This is actually a good thing. Because that's the way this industry works. Note the bad reviews on GD are from first time interns who failed to pro-actively volunteer/ask for assignments and/or feedback on their work, which the internship training program explicitly instructs interns how to do properly, and points out that it's a basic requirement for success at most internships and entry-level work in the movie business. But some people have trouble following basic instructions.