Its too bad people dont understand the search button, at least you know its there!
http://www.mazda3forums.com/index.php?topic=51193.msg814885
Couple comments from others:
""progress is the better choice if you are only replacing the rear bar, realize that ag_bullet has a stiffer FRONT bar also, so he doesn't have quite as crazy of oversteer as you would with just the RB rear bar and stock front bar. From watching him get used to his bar (we autocross at the same events a lot), I would think that for a car with stock Front sway, the RB rear bar would border on dangerous for street use only, if autox is important to you, then its something to consider (although I'm on otherwise stock suspension and progress RSB and LOVE it), but make sure you REALLY know what you're doing. If you're not 100% sure that the RB bar is for you, and have no plans of replacing the front bar too, then stick with the progress.""
"either will make the car stick. for daily driving I beleive that the progress is the better choice. Stability control will help but can take a lot the fun out of things whenyou are really pushing the car.""
"I had the Progress before the RB, so I can answer first hand. The Progress bar on stiff is great. The car is predictable and turns in easy with just a touch of off throttle oversteer. With the RB bar, things can get interesting fast if you are not paying attention. Go into an exit ramp a little hot and lift off while turning and be prepared to start correcting... The car is almost twitchy with the RB bar on for me. I had a rough time at the last autocross of the season with it. Now that I have the Konis, I stiffen the dampers up front and run a lower pressure in the back. The result is crisp turn-in but with better predictablility, especially at the limit.""
