The only aftermarket exhaust that I have heard on a Gen3 is a Full single M4 with carbon fiber muffler.
Guy who works at the local walmart has a few bikes, and I have heard him come in and leave, and on several occasions.
It sounds just like a Gen1 or Gen2 to me, to which I have heard Many different exhausts over the years, full singles, full duals, and dual slip-ons.
The M4 has a deeper tone than the Yoshimura, which has a slightly higher high rpm pitch.
Both are deep and mellow at lower rpm's, and both will scream up top.
The M4 sounds like the louder exhaust with the baffles out
Both get much quieter, and have a stockish tone with the baffles in.
