I am not familiar with this particular gun. However, I have seen other Armi Sport guns. I would not waste my money on the products. I think the barrels are accurate,(rifled) but the rest of the gun I examined left much to be desired.
With smoothbores, you are looking at balance and " pointability" of a gun, so that you can shoot both shot and RB in them. If the gun is too heavy, or too light, or doesn't balance well between your hands, its doubtful that you will be able to mount it to your shoulder quickly, and consistently each time, so that you can hit what you are pointing at. Muskets use a bayonet lug as the " front sight" that looks as wide as a house, on the end of that barrel, when looking at it from the other end! Without a rear sight, your cheek mounted on the stock's comb IS your rear sight. The gun has to fit you well if you are going to hit anything shooting round balls, instead of shot. I don't believe this " Musket " is a replica of any actual firearm built as a percussion smoothbore in the 19th century, however, and you might want to consider something else for that reason.