You are correct that the Savage is the only large scale production muzzleloader that will safely handle smokeless loads when the correct powder and loads are used. The problem is that there are some smokeless powders that respond similar to black powder (have similar pressure curves). Notice I said there are SOME and I said SIMILAR not exactly the same and not all smokeless powders. Smokeless powder is much more sensitive to pressure and loading areas and loading techniques than black powder or the substitutes so trying to shoot smokeless in any type in a rifle that was not designed and tested for that powder is just asking for real trouble up to and including failure of the rifle which can, and probably will cause severe damage to the shooter up to and including death. Not sure why anyone would chance this. As far as any advantage the only one is less corrosion or fouling possiblities but there are substitute powders that are almost as corrosion and fouling free. Blackhorn 209 (which has very suspicious similarities to smokeless powder) and the new form of Black Mag III which is now being called Black Mag XP which is soon to be available from MDM as they finally got control of the company and are now the owners. As far as comparing with centerfire rifles there is no comparison as the ballistics are way different even for the Savage. You just cannot push a .50 caliber bullet out of a muzzleloader as fast as a .30 caliber bullet out of a centerfire rifle.