We have inspirations. They may not last as long, but there's no penalty, and you can stack them. Not to mention this would, frankly, be seriously overpowered for some ATs. Overdrive plus Rage? Add to that a well-filled Fury bar?
(Also, really, most folks would just use Overdrive - if someone thinks their Tank or Defender is doing too little damage, they're going to hit the "more damage" button, not the "but it's better over time by this math formula" button. Besides, give me blues, Speed Boost, etc. and that "worse endurance" is severely lessened.)
Plus, using a PnP RPG as a comparison isn't really valid, if you will, as there's a human GM that can tailor and sculpt any encounter - if something's too easy, s/he doesn't have to wait 'til the scene is done to up the difficulty, or wait for a patch to adjust things.
This would also be completely useless to some ATs (depending on powersets) at low levels.
Prime example is the Fire/Kin Controller. At the Pre-Stamina levels, damage is already pretty low and endurance usage is high. I think even a 30% damage increase would not make much difference there, and endurance usage would be horrendous for such little benefit.
Likewise, with Conserve, sure the endurance might be more bearable, but the reduced damage would counter that benefit to where it would be totally useless.
Give all player characters unslottable inherent toggles called Overdrive and Conserve.
Overdrive increases damage maybe 30%, adds some accuracy perhaps +10% To Hit, and increases end cost of all powers by 100%. It gives you worse damage per endurance but better damage per second, representing the times when the hero (or villain) goes all out.
It should not be a sustainable way of life, even for a Willpower-er with Staminaand Quick recovery slotted, hence the large end cost.
Conserve decreases your damage output by 20% but gives you +30% on all end costs. It results in better damage per endurance, but a lower damage per second, for when the character is going slow and steady.
Both Overdrive and Conserve have negligible end costs.
Pros:
1) This helps out low damage classes like Tankers and Defenders in the early pre-Stamina game. They can improve their DPE by using Conserve mode.
2) It adds a tactical element to high level content - fighting an AV with a regularly recurring god-mode for example, you might pop Overdrive to try and get down that last sliver of health before they pop Unstoppable, even though it will drain you.
3) You can ignore this system completely and nothings changed!
4) This could be added as part of the main game, or as a bonus like the Mutant Super-Booster pack.
Cons:
1) Damage is probably not enough penalty. A team Controller or tauntbot Tanker could leave Conserve running without any penalty. Maybe need to add a Power Boost style effect to controls and debuffs to each as well.
2) Numbers would have to be crunched to make sure that there wasn't some magic spot where a power with say +50% damage and +50% end slotting was unanimously improved by either toggle.
The first Freedom Force had a similar system. Champions pen and paper allowed players to "push" their powers for exorbitant END cost, and both those features added a lot to the games if you used them.
Would this work here in CoX?