When I did our Grand Gathering for 13 a couple of years ago I booked all of our group meals through the Group Dining. My understanding is that, if you want to be seated together then you should go through Group Dining; if you use the regular Dining to make your ADRs they cannot guarantee that you will be together. It seems like the magic number is 12--I think if your group is larger than 12 then you need to use Group Dining. With that said, we ate at Chef Mickey's and Crystal Palace and had a blast

'Ohana and Whispering Canyon Cafe seem like great places for big groups, too.