I don't think the JP-4 was made to be the latest and greatest of all the JP pipes. The JP-4 is a 3 chamber pipe designed for Europe, thats why it has an EFRA number on it. Just like the Novarossi 9901 pipe (dual on/off road pipe). You can only use a 3 Chamber pipe in Europe now, because they are quieter. Noise is big issue in Europe. I believe a large race coming up was just cancelled becaused of the noise issue with the town. It may have better power in one area and less in another IMO.