The Dining Plan covers taxes and tips, so you are set with that. You get dining "credits" for each night of your stay, so you arrive Sunday and leave Friday so that would be 5 nights of credits. If you get in late Sunday and won't get to the park, well then you have a full days worth of credits to play around with during your stay. As far as "is it worth it or not" think of this; how many times a day do you eat in the park? Do you normally eat at sit-down restaurants when you are at Disney or do you like to eat at the quick service places? The Dining plan is worth it if you would normally eat one quick service and one sit down per day, for the amount of food you get, it IS a god deal, but if you think you would spend less than $38 a day per person on food, then opt out of the Dining Plan. We loved it, and will look into booking it again next year, but it's really up to you to decide!
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