[Feedback] Arms Warrior

Disclaimer: Some of this will be direct feedback, others may be general impressions and thoughts from my viewpoint as a theorycrafter, long time hardcore raider and all around leading authority on the Warrior class. Understanding that players of a different playstyle may have different opinions, my feedback is intended toward what I think is best for the game as a whole, rather than one specific subset of players.

First Impressions

Arms is a simple spec, but it works. In my opinion it feels much more fluid than Fury, and the major benefit is that it's abilities work in conjunction rather than in competition with one another. This is a prime example of how a rotation can be intuitive and engaging without being overly convoluted.

Please don't pull a WoD Alpha and yank this spec out from under us!

Synergy

I really love the amount of circular synergy the spec has, especially WRT the artifact traits. This is exactly the kind of beneficial "feedback loop" that I've been trying to suggest in the Fury thread.
Simply put: CS buffs MS and Execute, MS and Execute extend CS, everything resets CS.

At first glance this would make you think that, similar to Fury Enrage, you're left with nothing to do when CS is on cooldown. Arms saving grace is the simplicity that is Slam. It doesn't need a multitude of complicated mechanics (Furious Strike), charges or a long cooldown. It's a simple filler that gives you something to do, but can be immediately dropped when better buttons come along.

Artifact Traits

Shadow Slash: I really like it, though I personally don't like hoping for a proc on my AoE, which makes me think it should be 100% rather than a chance, even if that necessitates nerfing MS to compensate. I also feel as though it hasn't much use during the Execute phase, due to Execute being higher DPR than Mortal Strike.

Corrupted Rage: I like it. Great intent, good purpose. I'm very happy that it's off the GCD, as that allows it to line up without wasting time on things like Recklessness and Bladestorm.

Shattered Defenses & Precise Strikes: Because they benefit both MS and Execute, it works regardless of where you are in the rotation. Perfect example of Fury's problem WRT Berserking/Odyn's Champion.

Deathblow and Exploit the Weakness: Between the two you have the potential for a ridiculously long Colossus Smash which could last the entirety of the Execute phase. My biggest fear is that Exploit gets nerfed into the ground, but right now I love it's potential.

Precise Strikes, like Dauntless, only affects the base cost of Execute and not the extra rage conversion. Unlike Dauntless, it's effect is large enough to actually have a noticeable impact.

Void Cleave: There's nothing wrong with the ability, I simply find it bland, especially for a notable trait. It has no real gameplay or rotational value, as (tuning aside) we're encouraged to use Cleave against three targets already.
Suggestion: If ever there is potential for a more interesting artifact trait, I would consider clearing out this one.

Focus in Battle: It seems like a childish thing to complain about, but I find it odd that Tactician passive gives a 20% CS reset to basically every ability except MS, then a trait gives that same functionality to MS. It just seems like a lazy way to make up an extra trait. To quote my good friend WarriorSarri: "If that's your biggest concern, I'd be happy".
Suggestion: Similar to the above, if there's room for adding a new trait, I would consider replacing this one, and rolling its functionality into Tactician.