It's not true. Based on other threads and myimmitracker (more than hundred cases), there is no difference in processing time. Actually, it would be more helpful to track the application process cuz if received PAL and passed medical, it means only security check is left and at the last stage.
The known factors for delay are additional document request, number of dependents over 18, certain NOC, past occupation, past resident history (more than 6 months other than home country), VO and etc.
