Originally Posted by
Tiberria
As far as it being impossible to go OOM with Phylactery + Autoclave, it really depends. There is a lot of relatively short fights in this tier, and a significant amount of variance in healing requirements. In a lot of the really short fights, it is next to impossible to OOM with just a Phylactery equipped. For example, looking at Mythic fights:
Assault - Doesn't really matter what you do.
Iron Reaver - The fight is too short for it really to be possible to go OOM on.
Kormrok - An even shorter fight, with even less healing required throughout most of it.
Council - A very long and mana intensive fight (well at least on progression). Would want max regen for this.
Kilrogg - Next to impossible to go OOM - fight is relatively short and nothing to heal on half of it.
Gorefiend - Very mana intensive - especially if you are maxing throughput on the adds. Very possible to OOM and would want max regen.
Socrethar - Medium length fight, but not really mana intensive because most of the healing requirement is single target mana efficient HoTs on debuff targets.
Iskar - Next to impossible to go OOM. Fight is too short and there is so little healing required during most of it.
Zakuun - Next to impossible to go OOM. It's fairly healing intensive but is too short to really stress your mana pool.
Tyrant - Even though it's a short fight, P2 and P3 are incredibly spammy and healing intensive. Can use max regen here.
Xhul'horac - Really short fight and really lax healing requirements outside of tank healing until P3 (it's commonly 3 healed).
I haven't seen the last two Mythic fights yet, but out of the first 11, only Council, Gorefiend and Tyrant really have the healing requirements/patterns that would warrant using Autoclave + Phylactery. On most of the other fights, I would say that you reach a point where more Spirit doesn't really improve your throughput because you can't burn mana fast enough at appropriate times to take advantage of it.
Thankfully, the Leech trinket is so strong on progression that the decision is really taken out of your hands most of the time. 95% of the time, it's better to just use Phylactery + Leech on progression. Messing around with the class trinket and the other throughput trinkets (Felspark, Gift) is really only something worth doing if you want to try and rank.