You have already hit the nail on the head. Each gun is different.
I have used the Encore ever since it came out. Mine is a legit 1 MOA gun and I have killed deer with the 250 shockwaves and 777 out to 189 yards.
I just got the new duplex PR bullets prbullets.com
that are supposed to be the flatest around. Plus their website offers a lot of tweaks and lessons learned for all muzzleloaders, particularily the encore.
Personally, if your encore is shooting decent, what are you going to gain my buying the KNight, less than .5 MOA. Is it worth it?
Now if you are talking one of the new $2000 super LT Ultimate Muzzleloader or Bad Bull muzzleloaders then that is another story.