If it takes longer for our troops to lose, it means they're in the fight longer. And the more troops we have in the fight, the more our foes shall bite the dust.
Not to mention it seems to boost IC efficiency a bit, though I could be wrong about that.
Oh, it does boost IC a tiny bit, but with 100 IC, which is far more than probably any other faction, it's not as significant as it would have been earlier.
Combat doesn't seem to work the way that you think. "Takes longer to lose" means that it only helps when we won't be winning the fight, and basically just delays the inevitable.
I'd really think they'd be more useful, seeing as in the Fallout games mechanical implants are some of the most useful things you can buy. (See: Monocyte Breeder and Sub-Dermal Armor)
Considering the boost to toughness and defensiveness, I'm sure Combat Implants encompasses Sub-Dermal Armor. The problem really isn't the upgrade, but rather the upgrade in conjunction with this particular combat system. It's probably not as bad as I think, but it's not the tradeoff I really wanted. My prefence for boosters is always: More attack, less time, less cost.
Now, we're about to go to war with the Huns and the Mutants. As stated, my industrial capacity is probably higher than anyone else's, and I have all five research teams. I also have severe transportion shortages. However, I certainly could use the extra industrial capacity: I've just unlocked the ability to make nuclear reactors, and I'm hoping to build an airforce and a navy (my navy currently consists of three motorboats).
EDIT: Enclave has 60 IC, Polar Station Zeta has 30, Reavers have 100. Like I said, IC isn't as important as it used to be. However, Mexican Raiders and West BOS each have roughly 60 or more IC, and they are currently fighting each other. The victor of their little war could likely control more IC then I. Thankfully, I am currently at war with neither of these southern powers.
So, should I be seeking to annex or puppet the Huns and the Mutants?
Oh, and fun fact: The mutants have an airforce! Granted, it's only one air unit, but I'm quite curious to see what it is.
Guess which game mutants in biplanes reminds me of?