I have a 2.5 Hawk with PPP front sports cat and PPP rear box and have just replaced the resonated centre section with a Scoobyworld supplied Afterburner pipe with an integrated performance silencer. For me, this upgrade is ideal - it provides a moderate, purposeful increased exhaust note without in car intrusion. Should also give a bit more BHP. A couple of years ago, I fitted a Hayward & Scott straight through centre pipe, but the resultant drone was unacceptable and I reverted to the OEM section. For me, the new configuration is ideal - unless you are looking for loud!
John