Despite her being one of my favorite characters in the series, I'd have to say this is definitely annoying, and she usually only brings something up when it's suddenly relevant to Shinichi's case. It makes you almost question if she really is intent on bringing down the organization. I suppose this is probably more or less how Gosho decides to stall plot progression though.
I've noticed a genuine dislike of her character particularly from some Shin/Ran fans, but it's not as if Conan/Ai as a romantic interest will ever exist in canon. I don't see why other's thoughts on that pairing in particular should take away from her character.
I've found her character back-story and development a bit more interesting in comparison to the other characters in the series.