I never did understand the rampant Kaliyo hate. She amuses the heck out of me. To each his own, I guess.
It's not the character that is the problem, it's the class story she is part of. Kaliyo stands out like a sore thumb as a companion of the Imperial Agent unless you let her "taint" you.
This is essentially the case with all class stories, almost all of the classes have a companion character in them that sticks out a little too much that you might want to swap out for another one. Kaliyo, for instance, I gather would make more sense for a Bounty Hunter (better her than Skadge >_>) than the Agent. She might even fit better with the Sith Warrior.
Likewise, I'd switch out Rusk from the Jedi Knight for Yuun of the Trooper. Makes more sense to me.