The USB 3.0 ports can deliver better performance than USB 2.0 ports. Most routers struggle to power large, power-hungry HDDs ...

If you insist on using your router's USB port, there are two important precautions to follow. First, only use it for non-critical files. Don't share or transfer anything sensitive through the port.

You can do tons of stuff with a computer that most hardware NAT-routers cannot do, like having firewall software run on it, provide services (print (I know the SMC routers also have this), file, proxy ...