The only perks are comped meals and snacks during your shift. The job description is misleading. You start in the cafeteria busing dishes to the kitchen, taking trash, stocking ice, making coffee and tea, and stocking the condiments and silverware.
When you complete your shift, you go back into the kitchen to wash dishes.
If you're a hardworking person, you will never make it out of the cafeteria. If you're a lazy person, you will be kicked out of the cafeteria to work the catering department for the shows/movies.
The union is very weak. This is not the way to get into studio work. You are looked down upon and not respected as a hardworking individual with the potential for growth in other departments of the studio.