Okay, one correction. The pub in Killarney Ireland is Grogan's Pub. There is also Grogan's Grill that serves food. I've never eaten at the pub and I don't know that they have a full menu like the Grill has.
As far as the vouchers go, that depends on how big of an eater you are. I'm not sure it's a good idea in all cases. My wife and I usually get a "sampler" platter that has about three different things on it and split the meal. THAT'S a money saver. Also, portions tend to be of good size and you can easily get away with splitting.
Although selections are small, breakfast at the Squire's Galley in Banbury cross can be good. It's also a good place to get your bearings and decide what you want to do and figure out what shows you want to catch. (Easy answer: all of them.)
Das Festhaus is great for lunch to escape the heat as stated before. Aim for a few minutes after a show there ends (check the entertainment schedule) and it will have cleared out a bit. Supper at Restaurante Della Piazza in San Marco is great because, even though it's outdoors, as the temperature cools, it's really nice and the shows (Holiday in Roma and Starlight Orchestra), are great.
Overall, I'd say that the Trappers Smokehouse in New France is the pricey-ist. But the selections there are more different than anywhere else in the park. No show there though unless they've made it possible to see into the "Jukebox 2004" show in the Canadium Paladium. That would be a very small viewing area compared to the size of that particular dining area.
Yeah, I know.... I'll stop now.