we've done both goofy's kitchen & lilo & stitch. goofy's kitchen, we did for lunch. lilo & stitch, for breakfast.
goofy's...buffet, lots of variety of food, more expensive, food was good, more "lively", could be somewhat "noisy" for some, although we didn't find it to be, more of a party type atmosphere.
lilo & stitch...buffet, as well as you can order from the menu, DH ordered a burrito, and DSs & i had the buffet, food was breakfast type food (i think cuz we were there for breakfast...not sure if they are open for lunch?), food wasn't that good, (i don't particularly like breakfast type food), the stitch comes out every half hour or so, and gets the kids to dance or do some hawaiian activity of some sort, pretty small place.
both our DSs enjoyed both places, just as much. if i were to go for food, i would pick goofy's...