I never used an aftermarket. I ran my car at the track with no sway bar and noticed no gains in the 1/4. I barely noticed it was gone going around corners either. I wouldn't waste your money. Just spend a few bucks on poly bushings....but don't expect them to make a difference. They just give you peice of mind.
I just noticed the other day when I was under the car the front sway bar bushings are cracked. I figured the stock bar was just fine. I have to get a set of bushings, I think Late Model has them for $8 in polyurithane.
They are 29mm right?