My kids don't care for Biergarten, there's lots of German sausage and it just isn't their thing.
I've never been to Coral Reef, but if we were to choose from those 2 we'd choose Coral Reef next time, it looks like fun.
My kids really like the character meal at Garden Grill(?) at The Land Pavillion. Especially the young ones - they like the food, the moving floor and they always see Mickey at least twice.