John H:
I asked many questions of Gert before ordering his device. One query was to do with the centre silencer - here is his reply by email..
The center silencer of the PSE is internally almost a bypass, so replacing a PSE center muffler with a complete bypass will not give you a lot of difference.
Replacement of the centre silencer with the SharkWerks muffler bypass (i.e. straight-through X-pipes) is exactly what I did on my GTS and I can tell you from personal experience that it makes a dramatic and positive difference - methinks Gert may have been speaking to his own book. The fact that the PSE button still works is a good thing, as there may be times (few and far between of course) when you may not want to activate the sport exhaust - and, frankly, the day I get too lazy to press a button when I start my car is probably the day I should trade my 911 in for a nice comfortable SUV.