I feel absolutely awful for people who date high-functioning borderlines and never learn about it. At least with the ones who are low-functioning, you absolutely know something is deeply wrong with them at all points in the relationship. With a high-functioning one, you second-guess yourself constantly.
I really do think there needs to be more general awareness about Cluster B personality disorders. The occurrence rate among the population is low, but the nature of the disorder means a high-functioning borderline establishes relationships with (and potentially harms) a large number of people. It's hard for victims to seek help when they don't even know the name or nature of what they're dealing with.