I don’t think she has changed because what would the show do with a good Kristen? I think she’s still bad to the bone which makes for much better entertainment IMO (but don’t want to see her try to come between John and Marlena AGAIN, which I think is definitely the direction they’re heading).
Remember, she didn’t want to return; then she told John she came back to make thrings right with those she had hurt (now that she is changed). It’s all a setup to make other let their guard down.