The NRG is aluminum, that's why it flexes. The Relentless Autosports STB is chromoly steel and goes in front of the motor with no bends in the bar. That's basically why it's really the only bar that has a noticable impact.

 

^opinion

when I was at the Riverside Infiniti meet you could tell the difference when they were side by side. I originally wanted to get the NRG bar but the GT spec was WAYYYYYY more sturdy. Also the change in stiffness is noticeable in my sedan with the bar.

 

Not really, go ask all the owners of that bar and get their opinions. Search for reviews.