Isn't Jackson's blower a roots type style while vortech is centrifigul? Look at the power curves and decide what you want. I believe vortech makes bigger numbers, but at a much higher rpm than the jackson roots style.

 

yep, the vortech is more fficient.
ive also heard bad stories regarding the reliablity of the jr's

 

vortech with aftercooler, is way better than jrsc, turbo is even better