Figured I would start the thread even though it is early and set bonuses are like to change over the course of PTR testing.
Speaking only from my preferred clas and spec (Holy Priest) I don't see any allure.
The 2 set bonus for regen is tied to one of the worst spells possible. Granted there really aren't any other 2 minute CDs to tag it on to for Holy so I can see Blizzard conundrum here. My recomendation is scrap it and start over. I really don't get the homgenized regen set bonuses. I understand a lot of us want a regen bonuses but they don't have to be so similar. Tailor some regen bonuses that make sense within the class. Tying regen bonuses to Lightwell and power infusion is just silly.
The 4 set bonus for Holy is equally awkward reducing the CD on our holy word spells by 20% ? Really? The only one that tends to get used much is Sanctuary and only because it was ninja buffed and because Holy is more or less forced to use the AOE Chakra to be anywhere near competitve on the meters meaning Sanctuary is generally the only holy word spell at our disposal. We all know Sanc isn't a spam friendly spell and unless every fight in the upcoming tier is "stack for massive raid damage" not going to matter that much as compared to other throughput bonuses. Extra hops on PoM are also a no no this expac since there isn't enough pulsing damage to make it bounce.
How about a real mana savings such as every time a stack of serendipity is consumed you get mana back. Or for every missed bounce a PoM could have made and didnt when it falls of the target a percentage of the mana for the spell is returned. In other words if you cast PoM on the tank and thats all the further it goes you get 80% of the cost of that PoM back when it falls off the next target it never healed. I am sure I could come up with a lot more and probably way more off the wall but I think everyone gets where I am coming from.
Set bonuses should have some kind of wow factor and tangible benefits compared to taking their offset counterparts. Right now before the next-however-many iterations on the PTR I would skip the tier and just go BIS on everything whether it be tier or not since the bonuses just won't matter in t13 in their preliminary form.
On Resto Shaman:
2piece bonus is kinda the same for every healer class, healing cost reduction linked to your mana regen CD (except Priest, but as said, they don't have any other than Shadowfiend). Most likely (especially for less progressing guilds that might have trouble getting tokens for 4p fast) there will be a debate on getting 2 piece bonus vs getting offpieces with Spirit or other more preferred stats than the set ones. It also causes a lot of issues on e.g. 4min fight vs 6min one. One might favor set bonus, other might favor pure spirit. Gearing depending on fight length simply because of your mana CD? Not something to look forward to.
4piece is kinda ... weird.
It buffs our movement CD, but at the same time makes it a dual bonus one by also making it your only healing output CD. So unless there is a fight where you have to move 10+ seconds and do massive healing at the same time, you'll always lose some portion of the ability. Just ask Prot Warriors how they 'love' their Shield Block, Revenge & raid vs personal CD abilities dualities. Further more, the haste also brings extra mana cost with it, unlike the Druid, Paladin & Disc Priest 4p bonus. I really would've preferred something like "Your Riptide and Chain Heal now grant you 3 stacks of Tidal Waves", or basicly anything that isn't linked to a major CD.
Overall, the boni need work and I hope they atleast change some of them (especially looking at some healer & tank 4p effects)