I wouldn't call killing Jadzia a bold move, every show does that as a cheap ratings-grab when their regulars leave. Every crime procedural anyway.
Another Dax was the easy move, since every fan would already be emotionally attached to her. The harder move would have been to introduce a totally new character. Killing Dax was the most 'Standard long running TV show procedure' move DS9 ever made.
That being said I did like Ezri. Just, killing a character because their contract ended is the most fantasy-breaking thing you can do, and I prefer being immersed.