Pros
The people that work for the FTC are extremely dedicated, hard-working, and intelligent people who believe in the FTC's mission whole heartedly. They are readily available and willing to give you experience in areas of practice that you're interested in if that type of work exists. The training program that they run for interns is very good, and for an hour or two a week you'll be taught how the FTC operates from soup to nuts.
Cons
most of what I did was prepare powerpoint presentations from pre-existing reports or easily ascertainable data sources for team members who were traveling to various conferences to use in their presentations. While a practical skill, it does not utilize much in the way of legal intellect nor does it require a law school education to complete those tasks. I felt more like unpaid temporary office labor than a graduate student seeking a mentor relationship to further my legal career.