I have to agree with others here. I liked her, but yeah at her worst (or sometimes average), she was pretty boring at times.
I liked episodes where she got to do more, but 80% of the time she was only on screen because Miles was on screen. A couple of those TNG episodes where she got to stand on her own were fairly nice, if only because of the variety. I wish she interacted a little more with the rest of the DS9 crew outside of Kira.
In hindsight, I would have liked a Bashir/Keiko episode, in which Keiko's forced to take Miles' place in the adventure and the two end up bickering but end up sharing a laugh by making fun of Miles behind his back.