Mostly it's fluff, but Drow get some dialogue topside either forcing you to diffuse the situation or receiving assumed authority a few times, and Lolth-sworn have some good conversations with the other Drow true-souls, nothing drastically divergent. Gith get into similar situations with people, and other Gith, now that I think about it I don't think I've played a Gith all the way through, they might get more business with the goblins and the duergar.

I was looking forward to how a Deep Gnome would be treated at Grymforge, but apart from a few cracks, you're treated as a True-Soul first, even among the Gnomes, who kind of need to be reminded you're kin. Of course a lot of this is probably just what's in so far, Gnomes being just added, who knows.