Let me begin by saying that I think all the changes for arms were changes that the spec needed. It brings balance between talents much closer, and fixes the juggernaut absurdity of a stat that mastery was. That being said, there is a topic that I've been discussing with some people that I think really needs some attention and focus brought to it.
The Rage Model and Our Ability To Spend It
Arms in a fairly weird state at the moment with the PTR. But it all comes down to rage, and our ability to spend that rage. With all the changes to rage generation in regards to the Focused Rage talent setup, you rarely have the ability to use Focused Rage outside of Battle Cry, and using your normal fillers with MS/Tact procs between BC's your rage bar almost doesn't matter. But almost never quite generate enough to use Focused Rage in a meaningful way either. So you're stuck with a rage bar that serves almost no purpose. You either don't have the rage to make any choices, or everything is free so you're spamming everything...without making any choices.
The other scenario is with any spec that is not using the Focused Rage talent setup. With these other setups you find yourself in the perpetual situation that you can't spend your rage properly and you sit above 80% rage for a huge majority of the time. There is no choice to be made, there is no management, it's spamming your buttons locked on the gcd and hoping for Tactician to proc so you can hit a stronger button, but your rage bar never matters.
Why Is This A Problem?
This leaves you with no room to grow as a player, there is no goal, no flow. What is the point of the resource bar if it arguably serves no purpose? You either don't have the resources to make choices if you take Focused Rage, or you don't have the abilities to attempt to make choices without Focused Rage and sit at full rage all the time.
The spec devolves into a GCD capped spec where there is no exciting moments. There is nothing to think about. There's no management to the spec to think "what could I have done better?"
Again, I think many of the changes on the PTR were absolutely good for Arms in general. But a core aspect of the spec is supposed to be Rage Management or some kind of goal related to rage. Arms does not have that in the current iteration on the PTR.