I didn't quite like the exhaust note with the stock h-pipe. The engine was throbbing and sounding like a motorboat on idle, and on engine braking it produced a metallic rattle. On wide open throttle, though, it sounded perfectly okay.
A Borla x-pipe changed the exhaust note considerably, more of an exotic sports car sound at a higher frequency. This is due to the way the exhaust pulses are mixed with an x-pipe vs the h-pipe. In theory, the x-pipe should increase the exhaust flow due to better tuning of the exhaust pulses.
