The bigger the plan you get, the bigger your savings. When we used them two years ago, they were like using money, sort of. They are good for the value printed on them, and you don't get change. So, for instance, if we had a meal that cost $11, we would use two $5 vouchers and pay $1 in cash to get the most out of them. If you're careful, you can use them all and get a pretty good deal. However, there are some drawbacks. Depending on what time of year you go, you may not be able to use some vouchers. We went in October, and breakfast was not available at the park during the week--if we hadn't visited on Friday, we would not have been able to use our breakfast vouchers; also, the majority of the snack stands were closed, preventing us from being able to use our snack vouchers. The good news is that because it was off-season, the park Cast Members were willing to let us use the snack vouchers at the regular restaurants. We lived frugally on a four-day meal plan for four people, using only the vouchers (plus a small amount of cash) and eating only at the park, and had so many left over that on day five we had to eat at the more expensive restaurants in order to use them up.
My husband loved the meal plan, I found it a little stressful trying to make sure that they all got used. But he's a low-stress person, and I'm a high-stress worrier.