The great thing about them is their weight, or rather the lack of it!
As you saw, I bought a set of "lightweight" frame rails for my NB2, but really puzzled on whether I should install them or not. My car already has all the Sport braces, but some extra stiffness would be welcome. The thing is that I wonder if it worth the extra weight, effort and most of all the 20 holes (and the associated risk for rust) in my pristine floorpan. Anyone used them in an NB2 than can chime in? Car is a DD, with some occasional trackdays as a bonus.