My alarm goes off according to interruptions per attempted topic, especially those interruptions prior to The Point. It's not the tree depth or the level of antagonism; it's something more basic about respect, willingness to listen. Too many interruptions and I'll manually reset the conversation... not fun for me but it seems to work.

(In this, I assume people who know how to either tell a good story or reach The Point quickly. Blowhards are a different issue.)