If you are inbound to LAX from No. Calif., PDX, SEA, etc., you will most often be routed to the "24s" or North Complex, esp. if on the SADDE 6 standard arrival over Fillmore, down to Malibu and east over Santa Monica. This avoids SoCal Tracon having to run "squeeze plays" to weave traffic from the North over the final approach course for the South complex. It avoids conflicts with traffic set up for the South complex. SoCal may allow such crossover traffic at low-traffic volume times. Sometimes when it's busier, So. Cal will give a UA a/c the choice of flying east many miles (almost to ONT) to cross over to the So. complex approach course, or land on the North. But most often during busy times, such a/c just get sent to the N. Complex.