Is 1GB for the upload side? That's what will matter if you are trying to watch it from another location. That's really awesome. However, the SB network card only supports 100MBps. But, that shouldn't matter either - HD only requires around 10MBps for full 1080p (if that). I think 4K needs 10-12 Mbps or something like that.
If you are using it in your house, it will matter even less - the only communication that will happen would be over the LAN (which will max out at 100MBps anyway). I'm not sure about the other connected devices, but Roku also only supports 10MBps.
So, your primary benefit with the Fiber will be web browsing, downloading movies from various services and line quality.