It wasn't the prices necessarily, but wondering how long it takes. Our friends are bringing their 1 1/2 year old. I'm not sure she will make it though a whole meal! Also, we only have one day in the parks. Should we spend the time in a sit-down place? Or get something quicker so we can experience more?
I want to add to the mix of everyone's suggestions that it depends on what time you go, because depending on what time of the year you go, you could be waiting awhile in line. Then after that fact, you then have to find a place for seating and with the number of members in your party, I'm not sure how easy it will be to find a place where you can all sit together. However, once again, it depends on when you go and what time of day you go. For all I know it could be relatively easy.
I'm not going to suggest a quick service, or sit down restaurant in particular as plenty of others already have, but I just wanted to state this so you keep that in mind. Of course sit down will take a little time, but if anything you'll be able to sit down, relax, and possibly might have a little better quality meal for only a little bit more money. I would imagine with having those kids and you running around the park, it will seem very nice to sit down, take a breather, while you eat would feel nice. Even if you are on a time crunch. If anything, you can order something light, like appetizers, that way it's a little less and takes less time.
Personally for me, I do not eat a lot in one sitting anyway, as we're too busy going on ride to ride and traveling in the parks. With eating a lot, it might weigh you down and if you strain yourself too much you can get sick, especially on a hot day. I typically do not enjoy a big meal until towards the end of the day.
That being said, there are pros and cons for both kinds of restaurants. However, I just wanted to remind you that "quick service" is quick in the sense of you getting the actual food, there are other things that might slow down the process. Also, not all places, but I've been to a lot of places where the food you get is cold at quick service. And quite honestly, it makes me little annoyed when I paid $15 for perhaps just a burger and fries, and it has no flavor and has no warmth. But yet you can get something at Mytho's for probably 10x the quality for the same price. Luckily, the places people have suggested in this post I have never had that problem with.