Exhaust with MSD replacement: What's the point?

When searching for a sports exhaust system, I stepped on an exhaust with original rear silencer but replacement pipes instead of a middle silencer. The biggest problem: The exhaust is logically not allowed. But what takes me wonders now is whether it does sound and also does something powerful, if you don't have a mid-muffler. Own experiences?

If you're wondering why I'm asking this at all: On the Internet you can see many offers, where there is something of performance increase and bla bla, but it's usually only humbuk and not even noticeable in reality (in my opinion). Best example: I have mounted a different fan manifold on my Honda CRX, which is supposed to bring up to 12 hp. But I didn't really notice much of it, I had the feeling that I had less performance than before.

So now I hope for many answers

MFG Thomas