The Nighthawk is an awesome piece of consumer hardware.
However, it may or may not improve your gaming experience due to the fact that latency is a somewhat complicated thing.
Simplifying things for you, your latency in a game is determined by two things:
1) The ping from your device to your router (should be in the 1-2ms range even with crappy stuff, so a hardware upgrade won't necessarily do anything).
2) The ping from your router to the internet (which your ISP/line quality determines. If you live in an area with old copper lines, or just have a bullcrap ISP...I feel sorry for you because it's happened to me before.)