Depends a bit on companions aswell i suppose, those you get later have more drastic ups and downs. Ive never had such extreme gains or losses as 1k. I think 300 something gain with SCORPIO, she was the last companion i got and she gained affection like a potty trained labradoodle puppy.
Kaliyo is an anoying bitch tough. So often that i have conversation options and there is only a couple of wrong answers, that i lose affection. And the best answer for her simply doesnt lose affection, but doesnt gain either. I really dislike her...
Making the Light side bounty hunter choiche at the end of the class story gave something like -2000 with skadge. Gave + 1000 with blizz to and +500 with mako.