It also appears that some of the dialogue is quest-dependent. I had the following experience: whilst running the Tatooine bonus quests I passed a point where I hit no dialogue, but had to return to that same point shortly after for a different quest and can swear blind that I passed over the exact same point only to pop a comment from my companion. That makes this endeavor all the more... interesting...
I will say that one thing this has done is made the points where they say something more immediate. If they only say something once, it's a bit more, I don't know about meaningful, but I pay attention more.
I have some more for Dr. Lokin on Belsavis I'll be adding soon.
Edit: Updates in to Qyzen and Doc Lokin.