I'm sure many of you have already figured this out but I haven't seen it posted in a visible spot yet.
With the changes in 2.0 the new NanoInfused Absorb Adrenal gives a boost to Shield and Absorb whereas the old Rakata and Exotech Adrenals give a boost to Armor rating (which was then also multiplied by the stance modifier). I ran a quick test yesterday to compare the 2 and with my hodge podge 61/63/69 mix of gear I found the following:
Rakata Adrenal increased my K/E DR by ~6.5%
Reusable NanoInfused Adrenal increased my Shield by ~8.4% and my Absorb by ~7.3% each.
Now even with gear upgrades, the new NanoInfused is never going to provide a greater survivability boost than the older ones unless it is redesigned. In the mean time, I suggest anyone who uses these adrenals while tanking continues to use the older ones. On the plus side, they're now cheap as chips.
Huge thanks to KeyboardNinja for doing to full mathematical proof behind the concept.
Code:
In[19]:= abs[x_]:=0.2+0.5 (1(10.01/0.5)^(x/(55 0.65)))
In[18]:= shld[x_]:=0.05+0.5 (1(10.01/0.5)^(x/(55 0.78)))
In[17]:= def[x_]:=0.05+0.3 (1(10.01/0.3)^(x/(55 1.2)))
In[10]:= dr[x_] := x /(x+240*55+800)
In[31]:= mit[drBonus_, ar_, shBonus_, sh_, abBonus_, ab_, dBonus_, d_] := 0.75 * (1  (1  drBonus  dr[ar])(1  dBonus  def[d])(1  (shBonus + shld[sh])(abBonus + abs[ab]))) + 0.25 * (1  (1  drBonus  dr[ar])(1  (shBonus + shld[sh])(abBonus + abs[ab])) )
In[84]:= shadowBase:={name>"shadow",defenseAdd>0.11,defenseBonus>0.05,shieldAdd>0.15,shieldBonus>0.2,absorbAdd>0.04,absorbBonus>0.0404,resist>0.02,armorScalar>2.15, armorAdd > 0.04}
guardianBase:={name>"guardian",defenseAdd>0.04,defenseBonus>0.09,shieldAdd>0.19,shieldBonus>0,absorbAdd>0,absorbBonus>0,resist>0,armorScalar>1.765, armorAdd > 0.12}
vanguardBase:={name>"vanguard",defenseAdd>0.06,defenseBonus>0.075,shieldAdd>0.19,shieldBonus>0.0,absorbAdd>0.04,absorbBonus>0.1533,resist>0.04,armorScalar>1.775, armorAdd > 0.09}
diff[ar_,d_,sh_,ab_,base_]:=
(mit[armorAdd /. base, ar + 1675, (shieldAdd /. base) + (shieldBonus /. base), sh, (absorbAdd /. base) + (absorbBonus /. base), ab, (defenseAdd /. base) + (defenseBonus /. base), d] /mit[armorAdd /. base, ar, (shieldAdd /. base) + (shieldBonus /. base), sh, (absorbAdd /. base) + (absorbBonus /. base), ab, (defenseAdd /. base) + (defenseBonus /. base), d]  1)/
(mit[armorAdd /. base, ar, (shieldAdd /. base) + (shieldBonus /. base), sh + 375, (absorbAdd /. base) + (absorbBonus /. base), ab + 375, (defenseAdd /. base) + (defenseBonus /. base), d] /
mit[armorAdd /. base, ar, (shieldAdd /. base) + (shieldBonus /. base), sh, (absorbAdd /. base) + (absorbBonus /. base), ab, (defenseAdd /. base) + (defenseBonus /. base), d]  1)  1
{shadow>diff[2800,632,840,628,shadowBase],guardian>diff[5400,1126,840,134,guardianBase],vanguard>diff[5400,1033,840,227,vanguardBase]}
Out[88]= {shadow>0.11398,guardian>0.614459,vanguard>0.174525}
Just so you don't have to read the spoiler tags, here you go: {shadow>0.11398,guardian>0.614459,vanguard>0.174525}
So, the new calculation is basically considering the *full* mitigation profile (not including selfheal), assuming a 75/25 split on m/r+k/e vs f/t+k/e damage. I then take the percentage of mitigation increase from each adrenal, and then look at the ratio of these increases between the two adrenals. Loosely:
(mit[base + exoadrenal] / mit[base]  1) / (mit[base + nanoadrenal] / mit[base]  1)  1
Where mitigation is defined as the standard:
0.75(1  (1  dr)(1  def)(1  shld*abs)) + 0.25(1  (1  dr)(1  shld*abs))
Note that this doesn't consider resist chance, so it is *very* slightly inaccurate (the value of the nanoinfused stim is deflated by a miniscule amount), but it's pretty close to accurate.
The results show that the Exotech adrenal is 11.4% better than the NanoInfused for Shadows, a staggering 61.4% better for Guardians, and 17.5% better for Vanguards. So, your initial intuition was correct, grallmate, the Exotech adrenal *is* better, and by a fairly wide margin.
