I think what the above post means is that you could either save $10 off a ticket by buying online, or use the playanddine code, and get a free day of dining with a full price ticket. So that means, you are really getting the dining plan for $10 as otherwise you'd be saving $10 for buying a $10 discounted ticket.
Yes, otherwise the dining plan is $33 dollars plus tax. So, by buying a full price ticket with the playanddine code, you get all your food and non-alcoholic drinks for no additional cost to your ticket. A great deal, so saving more like $34 or so for each ticket bought using the playanddine code.
The food is good, and we did it on a long hot day, had B/L/D and too many to count stops for drinks (including water bottles) and snacks (fries, strawberries, cake)