There doesn't appear to be a "usual" settlement. From what I have been told the guideline is "in the best interest of the children". Until recently the courts often interpreted "in the best interest of the children" as meaning that the kids stayed with mom. In the past years, however, things have been changing and joint legal / joint physical custody has become more normal.
Courts have recently been deciding that "in the best interest of the children" means equal access to both parents.
Me 42, W 39, S8, S6, S2 M 11y, A & ILYBNILWY 11/08 Walking away from a bad situation.