Pros
Great people, all with a lot of experience, very willing to talk to you about anything. They are willing to give back to you as much as you're willing to put in. There is potential for a lot of great hands on experience. Though the internship is not paid, they dont sugarcoat anything, and there really is potential to learn a lot if you are willing to put yourself out there and make an effort.
Cons
Since the job is strongly sales oriented, the workload is sometimes unpredictable (which could actually be a good thing).