I've only played one game with her (30 mins, which happened to be cut short), but so far, my feedback would be as follows.
- I'd like to see the slow effect on her ult reduced in duration. Her ult seems strong as is, given the width and length of the AoE and the slow duration.
- I feel like her W would be more compelling if it had some sort of effect (besides damage) when it hit an enemy. It would make the decision re: who to target with her W more interesting, since right now, casting it on an ally allows you to proc your passive more frequently (ally -> enemy -> ally), whereas casting it first on an enemy only does a bit of damage and requires more nearby enemies to get the same # of bounces (enemy -> ally -> enemy -> ally). Not sure what sort of proc would be fair and interesting, given how much CC Nami already has.
- Also, another idea of interest would be to increase the effects of her W on each subsequent bounce, although that could become really strong in team fights.