Gigabit powerline adapter with Nighthawk EX7000 Extender?

I have ATT fiber and the provided gateway/router is installed in my basement. I have two other levels so I bought the Nighthawk EX7000. I have created two networks (2.4ghz and 5ghz) so I have the coverage. Now I'm looking for the speed. It will be difficult for me to run a Cat 6 cable to the ideal location for the Nighthawk, so I wanted to see if a gig powerline adapter may work so I could use the Nighthawk as an access point. Will it take away from my current speed by getting in the middle? Should I label the two new networks the same as my existing ones that I have with ATT? Other suggestions?