Frak off, I love both Ezri and Jadzia.
I can see how someone following the series as it aired would definitely hate Ezri. Jadzia was the best character for the the first six seasons, and losing her had to hurt. Rushing to develop Ezri in the last season would certainly not help, as it would seem like they were cramming her down the audience's throats.
But I only got into DS9 years after it ended, and went in already knowing Ezri would replace Jadzia. Coming from that angle, I may have an easier time seeing the faults and merits of both characters (and actressess).
Objectively, both actresses were often bad, in different ways. Terry Ferrell was often monotone, and Ezri's voice could be grating at times. And I forgive both, because Jadzia was fun as hell, and Ezri was lovable and interesting.
And while I love both Jadzia and Ezri, they frankly developed Ezri's character more in one season than they did Jadzia in six. Most of Jadzia's episodes were devoted to exploring the Trill in general; we learn very little about what makes Jadzia different from any other Dax host. We never met her family, or learned her previous last name onscreen. (I know it's given as Idaris in the books.) Even in the episode where Jadzia is separated from Dax, she spends most of it unconscious; that would've been the perfect moment to show us who Jadzia was, but all we saw was that she was "so alone" without Dax.
I agree with Seven of Five; they should've killed Jadzia and brought Ezri in earlier. Much as it hurts to see Jadzia go, they'd *need* to kill her and do a host switch, to fully utilize this character. I might not say that about another joined Trill character, but Dax was the first, the one from which we the audience would learn about the Trill through. I was honestly stunned when I learned that they hadn't planned her death from the start, and that it was just by chance that her actress was the one asking to leave.
That said, I am very salty that they didn't bring Jadzia back via a dream, or a Trill ritual, to interreact with Ezri. Farrell even said she'd gladly do a recurring role, she just didn't want to be a regular anymore. Why they didn't take her up on that offer, and give Ezri some spiritual/mental meet-ups with her predecessor, will forever baffle me.