I am going to reserve a 6400/6400M (not sure which yet) and this will be my first Flex radio. I'm not familiar with SmartSDR but assume you install the software on the PC and software communicates with the radio through the network cable.
Rod, it is a simple connection. I have my 6300 connected via a LAN cable directly to my internet provider's router. My PCs are connected to my home network on the same router. My iPad is on the wireless access of the same network. Seamless operation. Good luck and lots of pleasure!