Best answer by cam
No, it's all Ethernet so it doesn't matter really. Most nodes today have 2x10GbE and that should be more than enough. You might have a look at our networking best practices guide here: http://go.nutanix.com/TechGuide-Nutanix-VMwarevSphereNetworkingonNutanix_LP.html
Most customers today aren't using the 1GbE ports unless they need some physical isolation for maybe a handful of VM's. As you mentioned with security, let's say you have 5 VM's that need to be in your DMZ and your network team doesn't want to pipe DMZ traffic over a VLAN to the same physical network that your internal traffic is on - then we'd suggest configuring the 1GbE ports for that purpose and connect to the DMZ network.