among other things, the V6 differs from the inline-6 in terms of the timing of the exhaust pulses. The inline-6 has evenly-spaced cylinder firing: a cylinder fires every 120 degrees of crank rotation (it's a 4-stroke, so you need 2 revs for a complete cycle). This gives it a very uniform torque profile at the crank, measured against crank revolution.
in a V6 however, the cylinders do not fire evenly with respect to crank rotation. Pairs of cylinders will fire closely together, which gives it that rougher exhaust note. Since a pair of cylinders will overlap more on their power stroke, the maximum torque reading on the torque profile could be higher than that of an inline-6.
However, the flywheel dampens out these torque fluctuations, so we do not notice them at normal rpms. On cars without traction control however, you might notice the difference between the 2 engine configs when you do a tire-spinning start: because the V config has a more ragged torque profile (and higher torque peaks), i believe it will produce a more irregular tire spin than the inline-6. It will be noticable because at low rpms, the flywheel cannot smoothen out the torque fluctuations enough.
I've seen a slo-mo video of a Porsche 968 (with the biggest inline-4, it produces a ragged torque profile) on a tire-screeching standing start, and you could see the rear tires spinning and stopping repeatedly, each spin corresponding to one of those big cylinders firing.
an American V8 produces a "burbling" sound at idle because it has 4 pairs of exhaust pulses, each cylinder firing closely with its pair. The Ferrari V8 produces a different sound, because of its even firing order.
the best example of the effect of a V config on engine sound is a Harley-Davidson. Not my cup of tea though. For me, the best sound is a small-bore Ferrari V12 at full scream ...
also, the exhaust plumbing also affects engine output. You want to optimize "scavenging", and you would want to consider the firing order in designing the way the pipes merge.