Thanks for sharing your feedback on the bars and plates. I have the RD bars as well, but only have the front on at the moment. I've been a little gun shy to put the rear on for fear of inducing too much oversteer.
Does it feel like the middle setting in the rear gives you the sense that you're more on the brink of oversteering or breaking traction? Or is it really giving you that much more confidence to carry more speed? It would be an interesting test to adjust the bar from the middle to the low setting between runs to guage the effect.
What, if any, lube did you use on the sway bar bushings? I used a little silicone lube and it broke down fairly quickly and began squeaking. This is easily fixed in the front, but not so much for the rear.