Its april 2016 yet no healer stat weights???

[DreamWeaver]

Here's a crazy idea :

As a WHM, Spell Speed synergizes well with Crit.

As many people have stated before, healing in this game is scripted:
2 Cures here for the AA, 1 Cure II for the Tank Buster, Divine Seal Medica II for the raid damage etc etc and so on.

As we all know, Cure II is one of WHM's most MP inefficient heals, you basically pay extra MP to stay ahead of GCDs in these scripted fights, and 1 of the major things that push you to be behind in GCDs is tank busters.

Now, I would like to explore the interactions of each secondary stats (DET, SS, and Crit) with tank busters (I define tank busters as hard hitting abilities that hits so hard 1 Cure II is not enough to top up the tank).

DET:
If you're been using Cure II for tank busters previously, chances are even with a boatload of DETs, you'll still wanna use Cure II instead of Cure I. (I can't really provide an exact heal value here unfortunately as I'm not really aware on how much DET helps in increasing heal potency, but I'm kinda sure it's still not that great compared to 2.0)

SS:
With 888 SS, my GCD is at 2.3s, and my Cure cast time is at 1.84s, compared to a non SS character with (I am assuming, due to forced SS on certain equipment) 2.45s GCD, and 1.96s Cure cast time.
With that much SS, I am able to heal a target twice 0.27s (0.15+0.12) faster compared to a non SS character.

Crit:
Should I just cast Cure I instead of Cure II and pray for a crit?
If I Cure II and it crits, that's wasted overhealing.
If I Cure I and it doesn't crit, I'm behind in GCDs now.
decisions decisions.

The point I'm trying to get across is, with high SS, you are more flexible and am able to make more delicate adjustments to your healing rotations by virtue of your faster cast time.

Take the above tank buster scenario for instance:
If a player is geared for both SS and Crit, he may opt and plan to cast 2 Cure Is instead of 1 Cure II due to his faster cast time.
Now due to his high crit stat, the 1st Cure I ends up being a critical, thus he does not even need to cast the second Cure I now.

I don't think there's any other combination of secondary stats that allow for a minimal risk switch from Cure II to Cure I for tank busters:
Crit + DET : Cast may be too slow, if the 1st Cure I didn't crit, the tank may end up dying before your second cure lands.
SS + DET : No crit, best you can do is 2x Cure I.

In conclusion, I am personally going for a mixture of Crit and SS for now, due to its potential to change how we utilize our heals to be more MP efficient (Cure I for Tank Busters instead of Cure II) compared to other secondary stats, where if you're gonna cast 1 Cure II with X amount of secondary stats, you'll still cast 1 Cure I with (X+300) amount of secondary stats.

[Katlyna]

The point I'm trying to get across is, with high SS, you are more flexible and am able to make more delicate adjustments to your healing rotations by virtue of your faster cast time.

Exactly DreamWeaver. SS helps free up time for decision, movement, and adjustments.

I agree with you Lyrica, that in a perfect scenario there are a limited number of GCDs you can squeeze out and at some precise spellspeed number you would reach optimal GCDs with minimal idle/movement time, and excess spellspeed after this becomes "lost". The problem is raiding isn't a perfect world. Its highly scripted and damage is generally discrete but your team as a whole makes mistakes, takes more time for positioning sometimes, and less others. Extra spell speed helps give you extra time to perform your healing closer to "perfect" execution.

Anyway, Crit and SS both have serious merit over the other stats in my eyes (baring you have enough Piety to deal with your average issues). Between the two its very much up to personal taste. But both change your optimal playstyle slightly. Recognizing how playstyle changes should occur and reacting appropriately is the key to choosing and living with your ideal stats.