Range Extender recommendation for tri band nighthawk x6s model r8000p ac4000

[plemans]

I'm a fan of the triband extenders like the EX7500/ex7700/ex8000. 

Standard single/dual band extenders drop thoroughput 50% based off how they work. The tribands have a dedicated wireless backhaul just for router----extender communication. So they tend to be faster and have lower lag.