I thought the 9 year lifespan was brilliant, but they didn't use it as it was meant to be since on network TV they really don't let the characters change and grow significantly over the course of the series.
In one ep, we saw her potential, Before & After. IMO that was what they should have done in the 3 or the 7 seasons of the show. Let her grow up and then grow old.
Otherwise, I loved her spunk, she was the only one besides Tuvok who was willing to go after Janeway the way she did in season 1-3.
I loved her evil streak, the way she reprogrammed the doctor's holographic virus to give him a taste of reality, and how she teased him about what WAS reality at the end of Projections.
I was happy when she and Neelix broke up, their relationship just seemed "not right".
I did miss her and still think she might have proved to be a good counterpart to Seven instead of using the EMH.