My issue with HeatWave with is two fold:
needed to get up and close, Kaeris does not have the defense to be up close (missing Hard to Wound? Or opponents get negative to attacks against Kaeris?)
HeatWave upgrade is both 2ss and Limited.
I played with it a few times and their was one time it was fun to watch my enemies 12 SS be reduced to nothing. ... while it was fun, it took a lot of set up.
Conclusion the new models are going to help Kaeirs (all builds), they are more likely to help the best build and I have a hard time seeing fringe upgrades replacing existing. *I look forward to receiving my models and testing