The only inline I've ever handled was a friend's gun that he asked me to work on. It wouldn't shoot to the same place more than twice in a row, without being wiped clean. This was a T/C, too, so I assume a good-quality gun for its type. Kicked the living bejeebers out of me, too. The owner had gotten it from his boss, for Christmas, but when I told him of its cleaning fetish he said he'd switch back to his CVA roundball rifle.
I've had three friends, inline shooters (one still is -- like the Meat Loaf song says, "Two Outta Three Ain't Bad"), who looked down their noses at my flinters -- until they shot them. Even the one whose primary frontloader still has a plastic stock owns a .45 flintlock. The other two opted for sidelock percussion jobs and sold their inlines.
This is why I'm tolerant of inlines and those who shoot them. They're just poor, misguided souls who, with gentle persuasion and some patience, can be made to see the light.