I lost the text for the original 12.0.5 thread but not much has changed so this will mostly be a rehash of the points raised there. Before I go into detail, I want to commend you for the non-disruptive tuning of the spec this season. I truly believe this is an excellent approach because in its current state, Arcane is designed so badly and is so unfun that I agree with keeping it in its current unplayable state.
With that out of the way, the major issues (and boy there are many of them) that basically everyone in the community agrees on are the following:
Arcane Salvo and Arcane Barrage
Arcane was considered a very fun spec for the entirety of War Within, with the exception of the end of Season 1 thanks to the introduction of Aethervision. To quote your own words: We appreciate your feedback and patience as we continue to iterate on our 11.1 changes for Arcane Mage. The community has made it clear that Aethervision’s more prescriptive gameplay is not the direction they wish to see Arcane move in, so we’ve opted to retire it.
So what do you do going into Midnight? You introduce Arcane Salvo and Polished Focus, butcher Intuition (why is it not just the TWW version??? It was great!), and end up with the most prescriptive gameplay you possibly could. And not only is the gameplay incredibly prescriptive and boring, utilizing Arcane Salvo correctly sometimes just runs you out of mana (more on this below) and stops your rotation in its tracks. From what little I got to try in prepatch Sunfury soooort of gets around this with its higher CC generation and High Voltage procs, but even that is not enough to make the spec remotely as fun as TWW S3 Sunfury (which was very simplistic as well).
Clearcasting, Arcane Missiles, and Orb Mastery
AM being grossly under-tuned (as in between 5 and 30% behind depending on target count, with the larger gap being in aoe) means our only viable build removes one of four rotational buttons off our action bars, and spends every CC proc with Orb. In principle turning Orb into a strong damaging proc is an interesting idea, but the execution has been atrocious.
First, we get comparatively few procs because the CC proc rate and orb cooldown reduction are too limited for Spellslinger. Second, we have so few rotational buttons to begin with that we end up spending 60-70% of our time spamming a single filler spell. Third, it feels awful to have to spend five talent points (Arcane Missiles, Concentrated Power, Amplification, and 2x Apex points) that do nothing at all. Fourth, Orb has trouble hitting sometimes (e.g. if our target is floating), completely undermining the spec’s ability to function. I’m all for Spellslinger doing orb things and Sunfury doing missile things, but this implementation is harmful and unfun.
Apex Talent design
The rank 2 and 3 talent points do nothing for one of our builds, which feels horrible. The rank 4 point is completely opposite to how the spec should function, and how the first rank works: I am a burst spec and my damage comes in totm windows (rank 1), so give me damage within that totm window, not afterwards (rank 4).
Resource constraints and Arcane Pulse
The current design causes Arcane to run out of mana often, particularly when playing Arcane Pulse courtesy of its insane mana cost. If we run out of mana we can’t generate and spend salvo as effectively, which means we can’t get clearcasting procs and barrage casts as effectively, which means we end up having mana problems, and the rotation just comes to a screeching halt.
Hero tree tuning
Sunfury is unplayable. Its ST damage after the buffs is several % behind Spellslinger’s sheer mediocrity. It’s aoe damage is on par with tanks. This is caused by the catastrophic tuning pass you did back in December, which removed ~40% of Sunfury’s dps. Revert many of those nerfs, but in particular, the Glorious Incandescence nerf. If my salvo can stack up to 25, then I should proc a meteorite every 5 stacks consumed, not 6. It makes no sense that the first 24 salvo stacks I proc would be more valuable than the 25th.
Defensives
I discussed this more in the class tree thread, but the three specs having such a wild diversity in personals, and therefore in their ability to survive mechanics, is dysfunctional. Arcane currently does not have the toolkit to live remotely challenging content - whether that be mid-tier Mythic bosses like Paladins, or mid-tier keys. In addition, Spellslinger provides basically zero defensive benefit because of the insane nerf to Mirror Images that we took going into Midnight.
Unfun or non functional talents
Despite having one of the lowest number of talent nodes among spec trees in the game, the tree is littered with talents that just do not make any sense, or that either were made significantly worse coming from TWW, or that have been introduced without a purpose. In particular:
Orb barrage - tying the proc to salvo stacks instead of charges is depressing. The gambling part of orb barrage procs was one of the most fun parts of arcane, and now instead it’s just some passive proc I do not care about
Evocation - this talent is just worse than Mana adept at returning mana and does not provide any benefit otherwise. The loss of siphon storm completely removed its usefulness
Arcane Echo - this talent has been worthless and undertuned since TWW. Incidentally, if it were tuned well enough, it would make a decent replacement for the last rank of the Apex talent
Overflowing Insight - if this talent were tuned highly enough to be playable, it would also make our resource and rotational problems worse.
Charged Missiles - this talent just does not work with the whole buff stacking barrage damage thing that the tree is attempting to promote. Honestly there is no fixing this talent, just remove it
Mana Bomb - as my Arcane Surge comes off cooldown I will almost always be low on mana, therefore this talent does nothing. And yet it’s been in the tree since TWW
This spec has no vision to it. You need to decide whether Arcane is going to be some builder/spender thing around a stacking barrage buff, in which case allow it to neglect mana and copy SL Kyrian or TWW arcane, or if it’s going to be a burn/conserve spec where barrage is a tool to manage mana, in which case reintroduce some form of nuclear launch cooldowns a-la Legion, Dragonflight, or Venthyr Arcane. Maybe even go either/or with the Hero trees, but commit to something. Currently the spec tries to do both and succeeds at neither, and the problem starts from Arcane Salvo and its attached talents. Fix it.