Sway Bars

So exactly what question are you asking? What someone thinks is 'best' vs what they got may not be the same, and also what measure of 'best' are you looking for?

Kaz: I'm planning to purchase the RD sways later, I was wondering how does it perform on your car? Is the ride too harsh? How does it compare to the factory sport package sways in terms of the diameter of the bar, control of body roll and ride quality? Thanks for the info!

YMMV on a 330i, but they perform great on my car. Doesn't affect ride at all (sways shouldn't, really), and does a great job at quelling body roll. They are noticeably thicker than the stocks (I have SP), and they probably need to be to show that much difference. I originally ran the middle position all the way around but was getting too much understeer, so I adjusted the rears, and it's much better. Also, before I put them in, the tires (PZero Rossos) had awfully poor lateral grip, but work way better afterwards. Not sure why this is the case, (change in contact patch or weight loading, probably) but it was just as noticeable as the change in body roll.

Thanks for the info, Kaz. The reason why your tire has better lateral grip maybe because more of the tire touching the ground due to the decreased body roll. Where'd you get your sway bars? How much? What about install?