Almost exactly what my thoughts have been since beta.
Any discussion questioning the validity of current Disc doctrine doesn't end well here. Don't bother. The only responses you'll get are snide, counter intuitive replies that don't answer the question or show the reasoning behind why prevailing opinion is what it is or some snarky comment about you being bad and making a personal attack lol.
Such as:
That's a reply that implies that haste benefits other spells Discs use but not Smite/PWR much and thus haste is a bad stat if those spells are all that's used. Yet all other spells in a Discs arsenal are either not affected by haste at all or benefit more from other stats than haste. Logically and mathematically it's a stupid statement to make yet that's the reply that's given, or something like it anytime haste is questioned.
If you checked the numbers and ran a few scenarios for yourself you'd see that haste really doesn't do much to allow for more casts to be fit into an atonement window.
The difference between stacking haste and not stacking haste amounts to being able to cast 1 extra smite or (usually not quite) 1 extra PWR and getting 1 or (at most) 2 extra SWP ticks in a 15 second atonement window. Everyone makes out like stacking haste is game changing for a Discs ability to spread atonements but it's really not.
Most of the healing done in an atonement window comes from a CD like MB/Penance or LW and those either aren't affected by haste at all or are just barely affected.
The mana cost that comes with more casts, especially PWR, are the prohibitive factor when burst healing in atonement windows or setting up more windows. Not cast speed.
It's really not his responsibility to search for an answer because the answer doesn't exist. He can't find something that has never been posted. There is no mathematical or well reasoned argument as to why haste is better than any other secondary stat.
The only discussion surrounding it has either been based on laughably flawed logic like the notion that stacking haste is good and yet Discs should spend time not pressing spells at all in order to save mana or has been vaguely presented as good because it allows for more casting while ignoring the fact that alternative secondary stats have their benefits as well.
Even the notion that haste is amazing because it allows for more PWR spam before burst healing CD's is predicated on innervates but no one wants to say so. It's like everyone just forgets that spamming PWR before a 12-15 atonement burst healing window can cost 30% or more of your mana.
Now I suppose I wait for the responses to this post to be as woeful as they have been for VigilantRose's to which not a single mathematical or logical reply has been given.
This is where the haste argument falls off the rails for me. Stacking a stat that doesn't even effect some spells and is only useful for the other spells some fraction of the time while also burning through more mana than alternatives is laughable to me.