I am debating between the Borla Hush and the Maddad Whisper. First, will the sound differ from a WRX to a OBS (n/a)? If so, will adding un equal headers fix this problem? Finally any general opinions on the two exhaust systems? I know that they are both meant for the WRX, but there aren't many decently quiet exhausts out there for the OBS. Any and all advice is welcome.