The new bolt on 6236 is a GTX on steroids.. but at this stage too early to tell how long they will last or what times are to be had down the 1/4 Boost comes on much earlier and eliminates the lag us GTX users experience, peak power output more or less identical. Much better for a street car, but still I love the GTX and am happy seeing plenty of gts/clubbies/ss's in the rear view.