Since you are considering a Knight mountaineer you don't care if it's strictly a Muzzleloader. First off, the Triumph is a way better choice over the Pro hunter. Better made, more accurate, better trigger right out of the box.

The Mountaineer is a bolt gun and very accurate like the triumph. The Mountaineer does have better stock. It seems like a much better coating then weathershield. The Mountaineer does have a better trigger and adjustable. The Mountaineer is also Bh209 compatible with out having to do anything special.

The Mountaineer really wins in about every category except length. Knight chose a 27" barrel. The Triumph or pro-hunter is more compact of a gun. Of course they are break actions as well. The Mountaineer is a lot cheaper then a Pro-hunter and a little more then a Triumph.

Both guns will last a Life time, i would buy the one you like best. I own all three and the Mountaineer would easily be at the top. Pretty hard to ask anyone who does not have a Mountaineer. Maybe you should wait till more guys get them this month.