Hi may be too late now, but my daughter started at IBS in September. She went directly into 2nd having been in the french system since 6eme. Positives, small class sizes 15 for most subjects 5-6 for languages. Enthusiastic and motivated teachers. Downside chaotic organisation (my daughters view). On balance my daughter is very very happy and it really is a melting pot of different nationalties. My son will start next year. I would say though if your brother wants his children to learn french there is no better place than the french system, my daughter is in french mother tongue at IBS, having lived here for only five years and with english speaking parents.