The only Ezri episodes I don't like are the first one where she gets to the station, and the one with the vulcan serial killer.
At first it seemed like the writers knew they had so little time to develop her they had to shove her down our throats immediately, and that's how it felt after that episode. Then, ugh, that vulcan serial killer. That episode is terrible all the way through.
Starting out with the blatant 'frame the scene for obvious tragedy', then with Joran trying to Hannibal Lecter her by insisting that the fact that all the victims have emotional photos showing means that the killer is a vulcan, then '...It was the logical thing to do'. That episode is Threshold bad.
They did a generally good job with Ezri, but she wouldn't have worked well as a long term character since she has a job that has to use writearounds to participate in the action.