network through put.

This is not a specific question about Mikrotik but I hoping someone can answer me. We are using a Mikrotik gateway and using packet marking and mangle we limit our customers to various upload and download speeds depending on subscription. We have a backhaul that is quite slow and we want to improve through put if we can. From a network point of view would it be better to place the speed limits on the client unit rather than on the gateway