Echoing the sentiments that this set is cool as heck both conceptually and visually; an elec support set has been a long time coming!
Looking at the numbers though, it seems like it's being balanced in a vacuum. The best support sets in CoH have always been the versatile force multipliers: dark, kin, storm, time. Honorable mention goes out to several of the rest of them, especially the ones with AoE -res (which 11/15 of the support sets have access to). The ones that don't either bring very high damage bonuses (kin, nature) or are empathy and force field, which I think everyone already has an opinion about.
With that being said though, elec affinity's strong focus on being a buff-oriented set puts it in line with those two outliers, but mechanically, it still comes out looking worse than either of them. The value of its comparable buffs are smaller or more contrived, it has no defense buff, and it's playing at mechanics that would normally be featured in an attack set with no real payoff for the effort it takes when other support sets just have to recast their two minute buffs whenever the opportunity presents itself. I'll say that if healing had any actual value in CoH, elec affinity in its current state would be at the top for me just because of how easy it is to target people with the chains in a game where people tend to uh... spaz around a lot. But from the perspective of someone who has played every support set on the high end, you kinda forget the heals are even a thing, making half of this set feel skippable and the other half seem weak by several degrees.
Shock has very little value in a game where the reality is that a single enemy is never actually threatening enough to be worth the cast time to apply a damage debuff to it, many of which would resist most of the effect anyway. That same logic applies to the endurance drain mechanic; elec blast doesn't need any help with that anyway. (Try an elec/x/elec sentinel sometime, guys. They make sapping seem viable. They also make defenders look bad when they try to do the same thing.) If this power could chain, it would at least fall more in line with similar AoE damage debuff powers, but T1 powers in support sets are always a toss-up and this one might just be following suit.
Rejuvenating Circuit is probably the best direct heal in the game now, when you take a look at the full functionality of it and compare it to the way other heals operate. It's fast, it's AoE, and it does what it's supposed to do without any fuss. I still tend to prefer +regen buffs on the high end for covering incremental HP loss, but this one is actually fast enough that it doesn't bother me as much.
Galvanic Sentinel has me baffled. Compared to any of the toggle -dmg powers in most of the other sets, its discharge is anemic, and even if the debuff value was brought up to match (hopefully with some sort of addition, since all of those comparable powers also bring -tohit and other secondary effects), I still wouldn't use it. In any +4/x8 situation, this thing will drop in seconds. Its value when soloing is also dubious, considering how poorly the set handles in any solo situation as it is.
Energizing Circuit is the new transference, available super early and useful at least on the low end for the same reason: blue bar issues usually don't sort themselves out until you're fully built, in some cases with incarnates. There's some value in that, but on the high end that value falls off completely and the power becomes, like several others, skippable.
Faraday Cage is something new. I don't hate the power, at least now that it lasts longer and is fast casting. It still feels like a worse version of sonic dispersion, but that has more to do with how difficult it is for players to reliably herd themselves into the designated Good Places to receive the Good Stuff. I wouldn't expect anyone to stand in this for more than a few seconds, and the idea of having to recast it for every spawn isn't exciting, but on a design level it works and I'd be more willing to forgive it if the rest of the set brought more to the table and made this seem like a compensatory quirk rather than an intentional limitation in spite of its peers.
Empowering Circuit is busy, and there's no actual payoff for how much effort this one takes compared to other, similar damage buffs. On the low end, it's fundamentally worse than accelerate metabolism, siphon power and world of pain. Several other sets bring powerful single target damage buffs that you can spread around with enough recharge, and come with a load of other effects rolled into those powers. This one is basically a fussy version of assault. It needs to do more, and really when you compare it to its peers, it needs to do a lot more.
Defibrillate brings another AoE rez into the game, the value of which is dubious at best (howling twilight was always a viable pick for the -regen component more than anything else). This one has a unique identity compared to its ally-targeted peers, though, and for that reason it is at least logical. But it's still skippable.
Insulating Circuit is unique, and I like it for the same reasons I like rejuvenating circuit. It's still one-dimensional, though, and will serve very little purpose on the high end.
Amp Up is also unique, but its actual value as a T9 buff power is questionable. Many characters can't gain any real benefits from +special, and the ones who can are already built to take advantage of it (power boosted farsight, for example). An extra push in that direction wouldn't make much of a difference, and the impact on control powers isn't exactly game changing, either. The recharge bonus also doesn't compare to its peers. Other T9 buff powers have drastic effects—this one feels niche, but that has more to do with the realistic value of +special than anything.
Overall, elec affinity is trying to do things a little differently, and that's good. Those differences shouldn't have to come at the expense of actual usability, or versatility within the set, though. Many of the powers feel unconventionally one-dimensional for a support set, where it's common to find a buff or debuff power with three or more effects, and force multiplication is practically an expectation on the high end. In its current state, this set will have less of an impact than any other support set, for lack of any +defense, -res, and lower numbers on many of the effects that it does have compared to other, similar powers. And on the low end, force field is still keeping people alive better than elec affinity is. (And repulsion bomb is at least weirdly useful with procs in it.)
It just has me wondering: what does this set actually excel at? And perhaps more importantly, what should it excel at?