Some manufacturers place them to the rear of the hub/disc, others place them in front of the hub/disc.
What are the effects of either position?
Off the top of my head
1, positioning space comes to mind
2, weight offset in respect to other suspension components
3, hub design and force directions, for example, a caliper in front would have a tendency to try and force disc and bearing upwards(climb) in the hub as the pads try and stop rotation.
Anyone have any other views or wish to discuss?