Well I can tell you that ETS puts out the numbers to the point where I wasn't even aware they had dropped core size, fin design and end tanks with ets are certainly on points and they have a shroud to seal as well. Now is it worth the extra over the cpe well that's up for the person buying it to decide with their goals.I
Have my doubts about ETS doubling the horsepower gain with the same core thickness. CPE also has endtanks that flow very well, sealing shields and top quality fin design