Destruction Potion

Just think of it as a potion and not an elixir, will clear things right up.

Adept's Elixir, Greater Arcane Elixir, Elixir of Major Firepower/Frost Power/Shadow Power and Flask of Supreme Power all stack with this potion. Think of it less as a potion and more as an additional spell damage trinket.

You didn't really seem to understand the theory. :) Let me try and explain it again. The idea is to check if we can eliminate even having to do the hard math of seeing by how much one is better by seeing if they're even in the same ballpark, since what we really want to know is "is it better to chug super mana potions, or chug destruction potions". To do so, we can give the destruction potion side /ridiculous/ benefits (like calculating the benefit of it assuming you have a 100% crit rate, ruin, and are casting SB in the duration, which is a configuration that maximizes the return you could get from the destruction potion, but is obviously completely unrealistic), and see if it could /ever/ do better (assuming normal raiding gear) than super mana potion chugging with normal gear /without/ those unrealistic assumptions. Note that talent specs that affect /all/ shadow damage are meaningless to talk about as they affect them both the same, so you can skip making those arguments.

First, as shown, the super mana potion frees up approximately 2.25 seconds from skipping lifetap GCDs. And let's pick some spell to absorb that extra time - shadowbolt will do. That's 0.9 shadowbolts with bane. Could we do better? Sure, you could make all sorts of arguments about fitting in more beneficial dots into a rotation or covering for resists with high coefficient spells or whatever, but we don't care, as we're not attempting to maximize the super mana potion side of this, as we don't need to. We're making a very boring, run-of-the-mill baseline here.

Now on the destruction potion side, we make those incredibly unrealistic assumptions to show how much it could boost it by if you had impossible stats that would maximize it as much as possible.. and we come up with it giving us less benefit than our boring, run-of-the-mill baseline with super mana potions without those unrealistic assumptions.

The conclusion is that it's not worth doing the math to figure out /how much/ super mana potion chugging whups destruction potion chugging for warlocks, because we know that it /will/ whup it, and that's all that really matters.

If you're interested in the /how much/ for some reason, folks on the Elitist Jerks thread re warlock DPS optimization estimated that super mana potion chugging with normal raiding gear would come to about 30 DPS whereas destruction potion chugging would come to about 17 DPS (you can also use the popular warlock DPS spreadsheet to calculate the effect). Not exactly surprising how bad it gets beaten given what I already explained to you earlier. :) Here's a link to the thread:

http://elitistjerks.com/f31/t11799-warlock_how_do_you_do_high_dps/p66/

But remember, it's pointless to analyze those in detail and try and poke holes in them, as we know from what I've explained here that no matter how much you try and adjust their math, chugging destruction potions will never, ever beat chugging super mana potions (assuming normal raiding gear and a long enough fight that the mana can be used), as even by maximizing the return given stats that are impossible to obtain it couldn't beat it.