Nighthawk R9000 SFP+ Port

OK.... I have the R9000, and I'm having trouble understanding what this 10 gig SFP+ port is for.  I have 2 TP-Link switches with SFP ports, and use them with fiber interconnects, so I'm no stranger to SFP ports.  I have called tech support, and spoke with 1 guy who asked what s an SFP port was, and another who said that it was for a NAS device, such as a QNAP.  One simply connects an appropriate SFP+ module to the router, and one to your NAS, and you're off to the 10 gigabit file transfer races.  Please correct me if I'm wrong, but that SFP+ slot is the only 10 gig port on the unit.  There are 6 gigabit LAN ports, and nothing else that would support a 10 gig connection out. So, how does one extract 10 gig file transfers from only one port/connection that supports 10 gigabit? I was also told that this port is only good for file transfers, and is not considered a LAN port, as my switches consider their SFP ports. Could anyone please school me on how this port could actually be used? Is anyone making 10 gig file transfers? And, with what?  I did connect a gigabit SFP module from the router to my managed switch.  It shows a link, and that it is active.  But, no data will transfer. It does not stream internet. And no, I don't have a 10 gig internet connection. (it is 1 gig, though...)