Nope, you don't need them. It's considered a counter service. It's not really a buffet, though. You can order items from any station you want, but each item is priced individually.
You walk in the door, and someone asks you how many in your party, and will ask you if you would like them to explain how it works. You will be given a card and trays. You can go to the different stations, and order what you would like. The person taking your order will take your card, stamp it for the food item you ordered, and then they cook your order. If it will take a while, as in grilling a steak, they will let you know an approximate time to come back. A server may come to your table and get your drink order, and stamp your card. The server does not do much else. We had to go get our own drinks. Try the strawberry smoothies...mmmm!
We were on the dining plan, and it is great bang for your dining plan buck! I'm not sure how the vouchers work, but if it's simaler, you will be pleased, considering it is considered counter service. The portions are huge. Any non-alcoholic drink is included. It would be very pricey for people not on the dining plan who wanted to compare it to, say, Cosmic Rays, but the food is better there. Not as good as most TS restaurants, though!
One thing to keep in mind is that CSR is a convention resort. There may be a few times a day where it is crowded there, like when a convention lets out for lunch or dinner. But there is plenty of seating, and as you don't have real waitstaff, that shouldn't be an issue.
Enjoy!
