Ventajas
I developed the skill of letting everything that happened during the shift leave my mind completely as soon as it was over (honestly I had to as a full time student at the same time), but many of my coworkers found this difficult. You meet a lot of interesting people. You get a good sense for basic business skills.
Desventajas
There is little to (in my case) no upward mobility. My managers were very comfortable in their positions and weren't going anywhere. As a business student I would much rather work for a company that encourages both lateral and upward mobility. In contrast this company was very static in every job/role that I saw. I even met a quality control inspector who I (I think) blew away with my guest and customer service skills and he said he had come in from outside HI and had not changed his position for over 10 years. That's not for me, and I study Operations so if anything that would be my role in the company.