No, not at all underpowered. I was just wondering if anyone has used it, and also getting opinions on it. I'd also rather have the handling benefits of moving the engine back. I only know what the install instructions show and it looks like it does put the engine further forward, but on the other hand if it was similar in placement to the JCI kit and also let me run long tubes, then it would be a good option. In any case, as Cable pointed out, the headers are "still in development".