From what I heard, the English or American schools are the most appropriate for Western kids (and I include the Aussies, Canadians, Japanese, etc.) I believe the Japanese and the French have their own schools up and running along with the Indians, Pakistanis and Filipinos.
During beer sessions, I get to know the other schools are also good but the ambience is not exactly what your kids would like to have in age group of 12-18 and if you a Westerner. I hope you undertand what I mean. I suggest you have a word with other people you know and are ahead in Abu Dhabi.
Yes, they must be full and with a long waiting list because of the recent growth in the city being EY the most responsible for it.