Imo the experiences overlap. Many described as "classic" borderlines also have the same internalizing symptoms as those with quiet bpd. I act in AND out. Much literature does try to hop aboard using these terms to describe the different expressions of bpd, though the way the experiences are treated as completely different disorders is kind of misleading. Some literature believes self harming behaviors and suicide are things only those with quiet bpd do. I act out and I struggle with those symptoms, too. It's also weird how lashing out and black and white thinking makes you "high functioning". I've lost friendships, I've alienated loved ones, I think these symptoms lead to more isolation that I actually dread. Okay, I did read some of stop walking on eggshells and I found the categorizations of what symptoms are "high functioning" (acting out) vs. "low functioning" (acting in) quite messy and really misinformed. The author believes those with quiet bpd are low functioning though many on this sub who describe themselves as having quiet bpd have viewed themselves as higher functioning whereas those who exhibit more classic bpd expressions (lashing out, arguments with friends/loved ones, angry outbursts) have described how these symptoms of lashing out cost them jobs and relationships. I'd say I fit the category between classic and quiet. I don't know anymore. 

How do you all feel about these terms? Do you think "low functioning" vs. "high functioning" in relations to classic and quiet bpd expressions are really helpful or sort of divisive on who is suffering and who is not?