Sport mode and PSE ON is very loud.

 

Same here! My 996 C4S had stock PSE which back then was 'always on' and sounded great. I'd read (here and other places) about how 'dull' the interior and external exhaust sounded on the stock C2, and tbh those people are crazy. It sounds fantastic to me. I'm still itching for PSE or SOUL, but it's nothing bad as was prior reported, need to put that 'rumor' to bed! Especially in Sport/Sport+, that N/A engine roars!