I went from the PSE muffler hack to just muffler bypasses and haven't looked back. Yeah the bypasses are loud, but I'm used to loud cars and the sound is just amazing. I did notice a slight drop in the low end torque, but there is a top end pay off.
The PSE hack gives decent sound, but aren't throaty enough IMO. However, the bypasses put muscle cars to shame

My 996 is a semi daily, due mostly to the storms we've been having, but I have put 2K on it in the month I've owned it and 1.8K have been with the bypasses and I haven't gone deaf, but I may have caused a few other motorists and maybe a few pedestrians to lose some hearing, haha.