I'm talking about single player.
Half Nova is actually much better, especially on insanity difficulty.
The damage penalty of 40% applies to the BASE damage, not the TOTAL damage.
For example, the base damage is 100, and you get 100% boost through passives/upgrades/gears.
- Half Nova : 100*0.6 + 100*1.0 = 160
- Full Nova : 100*1.0 + 100*1.0 = 200
I did some test runs on insanity difficulty and found out there are hardly situations where Half Nova didn't manage to kill foes in one shot where Full Nova would.
Weaker ones die in one shot, stronger ones die in two shots.
In most cases the only difference is how much of their health was left after the first shot, and it really doesn't matter since they won't survive the second combo anyway.
Further, if you take full Nova, you are more or less forced to pull Nova out immediately after charge for maximum possible damage, but since Half Nova consumes 50% of MAXIMUM shield and NOT REMAINING shield, you can quickly fire a shell between charge and nova while not sacrificing the maximum possible damage at all.
I forgot to mention that if you pick rank6 pierce(you should), marauder/centurion's shields are vaporized regardless half/full or being the charge's target prior to Nova.
And again, the 25% cooldown boost of Power Recharge applies to the base speed.
Assuming you already have 200%+ boost, resulting in 300% cooldown speed, what you get through Power Recharge is 325%, and NOT 300*1.25 = 375%.
325% instead 300% is about 8.3% increase which is not negligible, but not considerable either. And this value is diminishing the more upgrade/armor enhancements are done.
You will probably play on insanity in new game+, with all the armor pieces purchased, all passives already at max at level 60.
To sum it up, BOTH damage and cooldown advantages of Power Recharge are diminishing the higher your level, the better your gears, and the more upgrades while Half Nova adds to survivablity and more importantly, FUN through crazy combos that would be too risky with Power Recharge.
True, the DPS might be somewhat higher with Power Recharge in GAMETIME, but the REALTIME DPS with Half Nova is actually considerably higher due to the fact that you charge less(less time dilation), and don't have to resort to HUD interrupt that much, at least for me.
PS1 : combos? Charge->Nova->Pull->Charge/Nova/(to a lesser degree)Shockwave. Hardly anything within the (multiple) biotic detonations survives.
PS2 : Charge radius wins hands down since Damage&Force charge will almost always push the victim out of the Nova's reach, even with Nova radius upgrade. And radius charge very often causes double (triple with luck) biotic detonations in the combo above.
PS3 : If you encounter a group of foes from some distance, pull, then charge. Starting with some nice biotic detonations, you will literally slaughter them in no time.
Did some more experiments:
- Charge base damage : 250
- Nova base damage : 350
- Half Blast's damage penalty : 40%
In ME3, active powers' gain/loss like Nova ALWAYS apply to the base damage.
Therefore, the damage difference between Power Recharge and Half Blast is stuck at 140, just like rank4 pick damage/radius.
My level 60 Vanguard's "least powerful" Nova does almost 800 damage as is with armors/upgrades. (radius + half blast)
Pick Garrus and Javik as sqad member, they add 10% damage each. Charge's Power Synergy gives 25%. There might be more upgrades. (Just finished Geth server)
So, the weakest NOVA does approximately 1000 damage.
For me, it's not worth heavily sacrificing survivablity and flexibility to get a damage increase of around 14%.
I think it's also obvious that the radius increase is more preferable than damage increase. 6.6m vs 5m might sound not too impressive, but it's actually 136.78m2 vs 78.5m2 which is more than 74% increase.
I might be wrong, but my experiments also indicate that the total shield strength doesn't affect Nova damage, just the percentage depleted matters.
If I'm right at this, it would be another reason to favor Half Nova, since it would almost always do its maximum damage while this might be not the case with Full Nova.