As you know, Patch 8.2 added new type of buffs for Heart of Azeroth called “Essence”. Most active PvE players already have collected and, because they really make a real difference, upgraded their essences to Rank 3. Let’s talk about the ones that drop from Eternal Palace. In order to get them, you need to get a total of 63 Aqueous Reliquary - 9 for the first rank, 18 for the 2nd rank and 36 for the third. Moreover, the relics drop only from three bosses: Radiance of Azshara, The Queen's Court, and Queen Azshara. In order to collect the required number of relics, you need to at least defeat Radiance of Azshara on Mythic Difficulty and twice from the beginning to the end clear Heroic Eternal Palace.
Let's look at these Essences and estimate how much influence they will have on the players and how much easier it will be for raiders to go through the Eternal Palace with them!
Vitality Conduit - Healers
The healers will receive the least gain from their essence. The problem is that Vitality Conduit is one of the weakest essences for healers, so raiders rarely use it. If the most essences increase healing, which is always required, then the Conduit works approximately like shaman’s "Spirit Link Totem ", but it redistributes the healing for only one target. The fact is that the essence is extremely situational. For example, if there will be a battle in the game in which a permanent debuff is applied, causing damage to one player once a minute, then Conduit will become always used on this boss. Yet it’s easier to take an essence that buffs healing and heal a target instead of this.
The verdict is clear - you should not use Vitality Conduit.
Azeroth's Undying Gift - Tanks
This essence indicates one tank problem. It gives good protection for a short period, which makes sense worth only in cases when tanks take a lot of damage in a short span of time. But now there are less and less such mechanics in battles with bosses. And the problem is in the fact that thanks to such essences, abilities, trinkets and other gizmos, tanks have too many abilities that allow them to survive huge instant damage.
Moreover, such tank abilities are sometimes not used at all. For example, it makes sense to use the Gift only when the tank is sure that now boss will hurt a lot. But most tanks already have skills designed for such situations. In addition, many other classes have protective spells that they can use and help the tanks. Given all this, we can all conclude that the Azeroth's Undying Gift is clearly better than Healers essence, but still situational.
Condensed Life-Force - DPS
When you open the third rank of this essence, along with it will open the road to raiding and high DPS. This entity is one of the best, if not the best for all DPS, provided that it is inserted into a major slot of the Heart of Azeroth. At the same time, this essence quite significantly increases the strength of the character.
The important is that the Life Force in general increases the player’s damage and thereby gradually simplifies the completion of Eternal Palace; first of all it helps with mechanics that are very demanding on the damage of raiders, for example, Lady Ashvane.
But the essence itself would not be such a decisive factor; it greatly helps players when combined with benthic equipment. Benthic items have their own bonuses, which are most useful to damage dealers, and can help slightly increase the damage output. Despite the fact that benthic item level is low, thanks to bonuses and sockets, which may or may not proc, they are being used even on the Mythic Difficulty.
Perhaps such a bias in the direction of increasing the power of damage dealers makes sense, because the success of the raid depends mainly on them. Usually tanks are dressed in pretty good items and can survive as long as necessary, and its preferred to take as less healers as possible to complete the raid, but DPS decides the comfort and speed of killing bosses.