We've had from 21 to 28 people in our GG ADRs.
During our 2007 trip I booked early dinners (some when the restaurants opened for dinner); and I felt they were pretty accomodating: LeCellier, Chef Mickey, 'Ohana, Boma, Prime Time Cafe, with seating us all close with tables pushed together.
Then in 2009 things had changed a little; when I called group dining to book, some of them made me call the restaurant directly

and i actually had to play telephone tag with them (LeCellier, WCC). But the others I was able to book through group dining - Biergarten, Tutto, 'Ohana, Nine Dragons, Cali Grill and Cindy's breakfast. I still booked early ADRs - but we never got tables together: instead they were usually near each other, but not always. When we walked in Nine Dragons the restaurant was practically empty and I
very nicelyasked if we could have tables pushed together and they said no

. The only ADR we all had together in a private area was Raglan Road; and that ADR I made online !