Well, as Matticus posted over on WoW Insider yesterday,Blizzard has updated the tier 10 set bonuses for priests on the ptr. I suspect a lot of priests will be much happier with the change, but I'm actually not very impressed. After all, only a few days ago I posted my initial reaction to the t10 set bonuses, and while I will admit that my excitement about seeing them sort of blinded me to many of the flaws in the bonuses themselves, my opinion really hasn't changed *too much*.
I'll start with explaining why the 2 piece bonus is so unimpressive.
"Your Flash Heal critical strikes cause the target to heal for 25% of the healed amount over 9 sec."
Blizz likes to dazzle us with crits, but as I've said before, critical strike is fundamentally a flawed stat for healers. You CANNOT depend on a crit to heal when you need that heal out there. Particularly at higher levels of spellpower and stats, too often the crit becomes overheal. Matticus points out that this revised set bonus is similar to the Paladin's Flash of Light on a target with Sacred Shield, which will give an additional 100% of the heal over 12 seconds.
The difference is, Paladins can count on that added healing - it is guaranteed, not based on chance.
So hurrah. Now when my Flash Heal crits, which is usually an overheal in and of itself, it will now overheal for even 25% more! Yay!!!
I say all this from the perspective of someone who raids as a Holy Priest, mind you. If you are a Disc Priest, this is actually kinda nice - an increase to your actually healing output in between shields.
I hate procs that are based on a chain of events based on a chance of something happening. I just get totally lost in the line of logic. Okay, so let me translate this to myself... If I cast CoH, there is a 20% chance i will gain some effect that will encourage me to cast Flash Heal sometime during the CoH cooldown in order to reset the CoH cooldown. Same goes for Penance.
Well, I will say that comparing this to the original 4p bonus, it is far superior (though it took me a few minutes to work that out for the record). If you forgot, the original 4p bonus was:
I can see why they made the modification - obviously there would be a significant portion of time in which I gain that proc when CoH isn't even ON cooldown, which is a waste. So, despite the mild complication of the tooltip, this is essentially the same effect, and has just had its proc improved upon to make more sense. That 15% number has been improved to 20%, which is also a lot better.
Despite the improvement, I wanted to recap something Betelguese mentioned in a comment. She (he? Oh bollucks) pointed out that while it sounds nice, 6 secs isn't a long time to take advantage of this proc. After all, you need to notice that it procced while waiting for GCD, and then cast your Flash Heal (1.5 sec unhasted) and THEN you can take advantage of it. Accounting for lag and attention span and all those things, you probably only have about a 3 sec window, practically speaking, in which to take advantage of this proc.
That is, of course, unless the orignal CoH that procs the bonus also procs a surge of light - and chance are, it will. At the T-10 level, you will likely have enough haste to speed up your GCDs a bit, and enough crit to nearly always proc an instant Flash Heal after CoH - especially since most priests who have the 2p set bonus will likely be stacking a bit of additional crit. Having said that, 20% still seems a little low to really make any noticeable difference, especially for a 4 piece bonus.
So overall, I stand by my approval of the 4 piece set bonus for the revised tier 10 priest set on the PTR, but I think the 2 piece is a waste, at least for most holy priests, although this likely depends on your style too. I know that most people probably much prefer it over the original Guardian Spirit/Pain Suppression version Blizz had, but in all honesty, at least in this scenario, I'd rather get the strong boost to a spell I use rarely but need in an emergency than a boost to a spell I use a lot that will mostly just be completely wasted.