I think you'll really see a difference. I have enough bracing now rear and front (and am adding hollow steel fender braces on the SCC car), I'm trying to think of a ladder style brace for the center of the car. Something like the GTspec stuff I picked up for my G Coupe.
Unless you have a cage, when you tighten up the front and rear of the B13 chassis esp running some fairly aggressive spring rates, the center becomes the obvious point of most of the chassis flex. Just drive one with beat door hinges and see how much more air noise you get cornering at speed vs. straight line.
Btw I dropped some blue loctite on those threads (the joint threads on each bar end) after about a year, and that top hardware is bulletproof - Chuck really spec'd some nice bolts for the upper mounts, after checking them a few times I've never had to go back and mess with any of the hardware. Awesome and effective brace.