What the person left out is that viability for shaman specs is largely volatile and varies from patch to patch.
Shadowlands saw a very strong restoration, but the introduction of a new AoE stack healer has all but ensured resto shaman is the worst healer in the game for both PvE and PvP. It feels awful in both.
Elemental and Enhance share a duality. Largely when one is good in pve, the other suffers…but conversely the one suffering in pve tends to do better in pvp.
Enhance largely has a history of sucking dirt in pvp and being incredibly harder to play than any other melee in the game. The reason for this is that it’s not an actual melee…and lacks most of the melee toolkits that help keep them alive. Instead, it’s a caster in melee range. If you plan to pvp at all on Enhance, be ready to be trained, and expect to only do well once you truly learn the spec, its nuances, and even then its an uphill battle.
Elemental on the other hand tends to always be doing somewhat well in pvp due to the design of the class. It’s a burst class by design, with lava surge mechanic being the core of the spec. That said, it currently suffers in PvE, but you can still play it. It’s AoE in m+ can be frustrating, a lot of players currently running liquid magma totem to get flame shocks rolling (otherwise you will be single targeting each one) and when you put down and Earthquake, the tank will mostly likely pull mobs out of it due to the simple nature that m+ is timed and you need to keep moving (or an affix requires it).
Thematically, shaman is the best class. Enhance’s playstyle is probably the most fun in the game, and I feel a lot of people will agree. There are several of us here, who even when enhance is not performing well in pve, stick with the spec just because its high APM, fun to play, and a visual fireworks show.
That said, if you plan to PvP, expect to be constantly targeted, and frustrated while you learn the class. If you plan to push pve content, either spec will work — but you may have difficulty finding groups simply due to the stigma that Shaman have (blue man bad) over several expansions.
Furthermore, at any given moment, much moreso than other classes, it seems Blizzard can and will break shaman for no reason at all (usually cause someone complained about something in PvP from one of the specs).
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