I shoot real black powder in my inlines. And then some days the wild hair pops up and I shoot sub powders. All depends on my mood.

The advantage of the 30 inch barrel is a more complete burn of powder with magnum loads. Although I believe a 28 or even a 26 inch barrel will do the same. It would be a long devil to carry around but I am sure you'd get used to it.

Although its probably another gimmick to catch the unsuspecting muzzleloader shooter in to thinking they have bigger and better.