I got a good deal on a used one that I run one on my 12 valve. I disagree that they are junk; entirely overpriced, but definitely not junk. I can take my AFC out and put it back in without any troubles, it's far from impossible. As for performance gains, I believe it feeds the rear cylinders better that the oem piece, but don't expect a huge gain from it. If you can find a good deal on a used one, buy it. I wouldn't pay full price for one however.