I liked Ezri. Would have been just as well if she didn't have the Dax symbiont but the writers handled it pretty well.
Honestly, while I liked Jadzia, the character never quite came alive for me. She was fun, and clever, but she didn't really have an arc nor much of a context. When DS9 began, I adored what looked like an interesting dynamic beginning--a wise old man, a "Merlin" if you will, within an attractive young woman. But she never fulfilled that role, not really. Nor did she really "do" much other than her job--at least until she started hooking up with Worf. I liked that storyline very much.
That Garak put Ezri down was a great bit of drama, though. It only worked because Ezri was indeed a real character, someone with those kinds of fears.