I like my plunger style guns. I use percussion caps in all of them.
I guess I like them for a few reasons, mostly because I just have a fun time shooting them which is what its all about.
The plunger style guns are a simple, proven design. A little dirty yes. Who cares. If I was to worry about that I may as well shoot a centerfire.
The plunger style guns I own are either White rifles with Wilson barrels or my Knight mk 85's made before they used the Green Mountain barrels. Two of them have Lothar Walther barrels and the other is made by Bill Wiseman.
I think all these rifles have triggers that are better than you get on any brand name muzzleloader you might buy today. They are accurate to say the least. I don't feel they are dangerous but I know their limits.
I guess that sums up why I love my plunger style inlines.
The End