I'm no expert on this, but I doubt that there will be any significant difference thanks to HW offloading on RB5009, if any at all. It doesn't have
L3 Hardware Offloading, only
HW offloaded vlan-filtering, i.e. if you'd have some VLAN on multiple ports, then L2 traffic between connected devices would be handled by switch. But you have just VLANs on single port, so any traffic passing through router will use routing, i.e. software processing. Anyone please correct me, if I missed something.