If you go on a day where the park opens early and closes late (10am-10PM or longer) then the meal plan is easily worth it. Get to the park early, eat breakfast then enjoy the park. Midday grab a good lunch. Just before the last evening show plan on having dinner, then head to show before leaving park.
On short days 10am-6pm it is not worth it. You cannot eat enough to make it worthwhile. On shorter days do buy the cheapest souvenir drink tumbler. Refills are free first day of use and about $2 other days. Saves quite a bit.
Meal plan allows you to get one entree, one appetizer or dessert and one drink once per hour. In between meals we grab a drink only. Don't bother waiting in the line if all you want is a drink. Just go to front, grab drink and show wrist band to CM at register on way out.
If you buy an annual pass there is a discount on the meal plan or drink tumbler.