Pros
Camaraderie- you develop friendships and strong team atmosphere with coworkers. Learn to deal with stress and constantly evolving schedules and responsibilities. Experience- great real world experience learning regulations, logistics, and customer service. As an E.S. you learn to interact with both blue collar and white collar clientele. Education- they provide numerous training opportunities and valuable education reimbursement.
Cons
Hours- 50-60 hour work weeks. Many days I would arrive at my first site by 5am and not be done with my day until 6pm. Pay- starting pay around $15.50/hour, you have no choice but to work overtime in order to make a decent pay check, which they've already scheduled you for. Office politics-it takes a long time to build your name, but only a few seconds for the cooperate people to turn on you. You'll be "thrown under the bus" without hesitation by someone else to make themselves look better. Unless you quickly move up the ranks and find a salary position in office, my advice is to stick it out for a few years to gain some valuable experience/training/education and then look for a new job.