Two of my friends have them on their Dakota's
They said they didnt notice any more performance.
They are just about the same loudness as any other aftermarket brand.
One set has over 40000miles on it and it's still like it was when he first got it. No holes, corrosion etc.
His installation is very clean and neat, (welds etc) but that seems to be in the hand of the person that installs it.