Pros
You're not heavily micromanaged and can take your two 15 minute breaks. The work isn't that hard, depending on which client you work for. Some accounts have opportunities to work later hours.
Cons
The pay is probably the worst thing; this is a sort of job you should take only if you have nothing else lined up. They'll hire almost anyone because there's such high turnover. Parking is terrible. You should plan to get there at least 10 mins before your shift starts because you might get held up going through security. They won't allow you to have food (or anything - you have to put all your belongings in a locker, including your wallet and keys) at your desk, and if you're drinking something, it has to be in a clear container with no label on it. You're not allowed to have any pens/paper at your desk either because they're afraid you'll commit fraud (even though they ask you a million times if you're a criminal in the interview process).