Adloquium is extremely inefficient unless you crit.

It is depressing, and also doesn't stack, which is one of the main complaints scholars have (esp dual scholar parties).

If you play WoW or other games, Adloquium is closer to a Flash Heal rather than a Greater Heal, or even PW: Shield.

Physick is 400 potency, Adloquium is 300 + 300 shield, but costs nearly three times as much.

Assuming 15%ish crit chance, Adloquium's average healing is

.15*1.5*(300+600) + .85*(300+300) = 712.5

While for the same mana, 2 Physicks is 800 potency.

So with adloquium, you trade efficiency for bulk healing (regardless of crit, adloquium IS more healing than physicks over the same GCD).

It is certainly not sustainable.

Succor is a bit better, but again, only works well on sustained AoE damage (Titan stomps, for example), but is extremely inefficient if used to heal up after large AoE damage has hit.