Gen 5 Camaro External Bolt-On Tech - Qtp low profile cutouts and not impressed?

So a buddy of mines got them put in today and sounds just like a regular exhaust coming out the back? It sounds pretty nice once in the high rpms but ints just not loud? Do you guys think there is a possibility that the muffler shop didn't cut out the holes big or clean enough for it to flow out the bottom? Thanks for you guys input before hand.

did they put them befor the cats?

No because he said it would void his warranty?

Kind of makes it pointless then, I would think somewhere before the x pipe would be ideal…(just a few feet from the headers)??

The cats quite it down they act almost like another muffler