The Food and Wine Festival is free. The Party for the Senses that occurs on the weekends is an extra ticket; a pricey one, but really worth doing at least once.
During the Food and Wine Festival there are additional food stalls that don't normally exist. In the past they've had a wide variety of mini-foods that are offered for under $4.00 each. I remember having MD crab cakes at one stall, and cheese soup from the Canadian restaurant from another. China had some type of chicken. There is a variety of beer and wine as well. My husband litterally grazed his way around Epcot a couple of years ago.
I can't think of anything negative about it unless you consider that your eyes maybe bigger than your stomach.