My biggest gripe with the Bionic Slot system isn’t the system itself (I actually used it for my own game, Genefreaks, because the Shadowrun/Cyberpunk 2020 way of doing it never made sense to me). Rather, I think a lot of the CBMs take more space than they conceivably should, while some take up body portions that make sense on a surface level but seem like they could be trimmed for gameplay’s sake.
Cut down on a lot of the spaces by half, and I think you’d be good. I can’t see a good reason that Wired Reflexes would take 8 leg slots.
My other way of balancing CBMs (which I’m far more in favor of, personally) is to make it so taking electrical damage is worsened significantly for every CBM you have that’s metallic and/or hooked up to your central nervous system. Get hit by that Shocker’s Zapback with no CBMs? You might live? Have all four alloy platings, all the different enhancers (stat boosters, targeting system, etc)? You’re going to be risking your life by getting zapped. And this would also require making it so the Dielectric Capacitance System no longer grants immunity, just an enhanced resistance to electrical damage (which, if you have enough CBMs, isn’t really going to help you).
The issue with most proposals is that they don’t provide a reason to not install CBMs. While the slot system forces you into an economic decision, it still doesn’t force the decision “should I install this or not?”.
Power Storage is another animal entirely.