Pros
They tend to pay a bit higher than the other companies in the area pay. They have benefits too, medical, dental, vision, disabilities insurance and 401k plan. They actually do try to not hold you over due to call offs if they can help it which is RARE in security. Usually if someone calls off other companies just tell you "well looks like your doing a double" and that's it. They usually try to get you a replacement ASAP which is good.
Cons
No real training. They train you how to do your job but that's it, no personal development stuff. They don't have a good way of knowing about promotional opportunities unless you kind of stand out from your peers and are approached by management. Senior Management was good, but managers and site supervisors were not the best.