Pros
The internship was completed during my sophomore year in college. Compared to other students, the pay was pretty decent for 40 hours a week. They were extremely lenient on taking days off, which was a plus during the summer. The firm is very prestigious and well know among the industry and access to senior executives was very easy (often had lunches with partners whom worked down the hall). The work was interesting and there are always events for interns such as a trip to DC, BBQs, trips to see Nationals play, crab feast, etc.
Kontras
The security clearance is a problem. It takes 3-4 months for each polygraph so unless you were hired early on and passed on the first try (many take more than once to pass), you may be stuck doing unbillable work which is not nearly as exciting or important as billable work. Fortunately, you still get paid the same.