From what I have seen,if you choose to go the Vortech route,you get to keep the Bullitt's trademark intake manifold,a good thing I like. However,you have to send out your factory computer for a reburn,once done it is that way forever? Suppose down the road you want to put it back as before? With the Roots type deal,you ditch the stock intake,and use a different computer,like the FRP deal. What is the typical life span of a Vortech type unit? I guess the engines give up long before the unit!