I find that there's not a ton of dialogue or events from each follower or npcs regarding each follower, but they certainly took the time to put many where it counts. Like how elves treat dwarves, or good npcs treat evil followers, and so on.
A follower based event I just had happen in a playthrough:
There's actually a special dialogue comment from Simeon Tor in Tulla if you arrive with both Geoffery and Perryman in your party, who both spent time in Sulla before.
Perryman WILL NOT join your party if you are not good aligned, and Geofferey WILL NOT join your party if you are not evil aligned. So you have to be evil and get Geofferey, then once you get to Perryman you have to work on changing your alignment to good.
Then, Perryman WILL NOT join your party if you have Geofferey in your party UNLESS you have 20 charisma and he will make an exception (that's the only thing that did it for me).
So it seems that Troika even took the time to put in a special dialogue for the one player who would steer the course of the game in this extremely specific way who would spend the time to both lower and raise alignment and dropping way too many points into Charisma just to get another mage follower.
That is really detailed and dedicated.