On AP Regen

There are now a discussion thread on AP regen on the official forums.

From 1.3.1, there has been a problem with AP regen, with everyone effectively having unlimited AP regen.
It's until a day ago when Mythic implemented a fix for the regen problem, and surprisingly for me the player reaction so far is very divided. Some don't like the change, citing it came out of the blue without any testing on the PTS, while others hate the change because they think the changed combat is too slow and threaten to cancel.
This latter opinion is what initially shocked me, but I have to say I wasn't really surprised after thinking about it. It's just a matter of habit, for people who started playing after 1.3.1, or people whose class have a number of high AP abilities, having unlimited AP is easy to get used to. It is kind of like cheat codes in single player games - once you have "tasted the power", it is hard to go back down. It's really not that different from being nerfed.

Musings aside, what interests me is the mechanic itself. The AP regen system as I remembered is this:
0 AP during GCD and channeling
normal AP during casting, autoattacks and when not doing anything in combat
fast AP when out of combat

And in this post, EricS mentioned Mythic's intentional AP regen system:

AP Regen Rules and Regulations:

AP Does NOT Regen When:

- During Channeled Spells

- During Ability Cast Times

- During GCD

AP Regens:

- After a GCD

- When not using abilities

- During Auto Attacks

- Eric

So either I remember it wrongly, or Mythic's AP regen system is not what they expected since launch.
This is very interesting, because AP regen system has very far-reaching consequences on all classes. If they changed abilities with a "broken" AP regen model in mind, they would have to be changed back after fixing the AP regen. One example is the spam ability of SH/SW, Plink and Eagle Eye. Their AP costs were increase in 1.3.2. With the fix yesterday, some are reporting they are unable to fire more than 3 or 4 before they have to wait for regen again, as opposed to spamming it indefinitely. If you can't spam a spam ability, then the builds have to be adjusted, and that would be uncomfortable for many players, and the balance would be further affected.

In my opinion, what Mythic should do is to collect info for around a week, and be ready with an announcement. The info they should focus on should be:
- how "spammable" are the spam abilities now? Especially for classes whose abilities got their AP cost increased. This includes DPS and healer classes.
- how effective are classes with AP regen abilities as opposed to those who don't? Classes like BW/Sorc can gain AP relatively easily, WP/DOK have always been managing their AP, and tanks in general are less taxing in terms of AP. Other classes would have a more difficult time face with this change, and thus need more information on how they fare.
- do this change have an effect on the TTK in general? If not, it means there are more problems than AP regen, and making the change might not be the best solution to push forward.