I started with the old cap lock, moved to the Knight disc and moved up to a Encore and than to a Traditions Prusuit and on up to the first style Pro Hunter. The latter being my pick out of every ML I've had the pleasure to own. The Knight had few different style BP's meaning the fire path was larger or the back of the BP was more open or the back was split supposedly to help lignite the powder. The Traditions if the BP got worn you have to pry the primer out. All these ideas in my opinion came to a head w/ the Encore/Pro Hunter that will all but flip your primer out. The Idea of being able to remove the BP w/ my hand does influence me to not ever buy a ML that has that feature. If I can't carry a BP wrench then I shouldn't be hunting. It also allows for more blow by. Manufactors need to forget the speed breech and move on to other improvements. The thing to remember is what ever BP you have is keep it clean and the threads greased or taped. If the ML was designed w/ that plug then you might improve it but in the end is it worth the expense. The main thing in my book is the speed I can remove & replace a primerbecause w/ a 209 misfires are rare.