The only main character I ever had any negative feelings for (or should I say just couldn't be bothered with) was Jadzia.
There wasn't any point to her. She could've been completely removed for the show without changing the narrative much. It was obvious the writers didn't know what to do with her because they reinvented the character four times in six years.
Ezri was had so much more potential from her onset because the concept of a Trill who viewed symbiotic-joining as a burden instead of a gift was so much more interesting than anything Jadzia had to offer.
I reckon that, had it not been for the overwhelming admiration for Farrell, Jadzia would have been dumped a lot earlier in the series.