While noise does not always equal power, there is a direct relation.
But really, it is not about being loud and abnoxious, it is about power.

I was running a V&H 2 into 1, which was nice, but after switching to the thunderheader... that flatspot at 2500-3000RPM disappeared.
Sooooo nice!

For me, I like the torque aspect of harleys. Low end power is diferent than top end.

Again, just a matter of what a rider prefers.

I have had my XL 1200 S for 11 years and it has been very reliable.

But now i want to see what all the fuss about Ducati is!