I liked Ezri more than Jadzia, too, though I agree that she was kind of rushed. I understand that was kind of the nature of the situation, but in retrospect if they'd known Terry Farrell was leaving the show when they were writing Season Six, I wish they'd just killed her at one of the other two near-death experiences she had in "Rocks and Shoals" or "Change of Heart" so that Ezri would have had a little more time to get introduced without taking up as much of the final season as she did.
It would have been more daring if they'd replaced Jadzia with a male Trill, though I get why they didn't do that. Nana Visitor would have been the only female regular if that had happened.