I have also been through the family court system and the magistrate decided that my son can stay with his father. She did concede that he had a drinking problem and should refrain from drinking over 0.05 levels while my son is with him ... and this he is supposed to self manage!
So now my ex is unemployed, living in squallor, drinking to his hearts content and my son is raising himself. My advice to any mother that thinks they are doing the right things by letting their child try living with their father - be very, very cautious. You may never be able to get them back.