CGP will give you real work, not just office/admin tasks. The work can actually be pretty in-depth. CGP will also get its interns involved in important tasks/meetings/collaborations within the company and with its partner companies. I definitely feel like the things I worked on during my internship are things I can talk about on job applications and in interviews.
Cons
The work CGP gives its interns is very open-ended, including intermediate goals to reach on the way to completion, and it can seem both overwhelming and hard to navigate through if you're used to any kind of directed management style.