I have the 403 HoU so for my other trinkets it's between Seal of Seven Signs (397) Foul Gift, DMC Tsunami, or FQ. I have been running with Foul Gift because of how often it procs and how good mastery is for Holy, when I don't use this trinket there is a noticeable difference in my Echo of Light healing done %. Usually I do around 15% done and without it on madness I only did 13%. TBH I think the WWH might be useful but I ended up giving it away after the raid to a shaman healer...was this the right decision?
I would think it depends a little on the fights. My opinions on each trinket (aside from HoU, since that should definitely be one of your equipped trinkets):
Tsunami Card - I'd use the Tsunami Card on a fight where I really need the regen since it's your only other regen trinket.
Fiery Quintessence - I am not a fan of non intellect or on use spellpower/int trinkets, therefore FQ is out for me. I prefer intellect based trinkets over on use throughput trinkets. Foul Gift - I've never given Foul a shot since I have had two heroic FL trinkets since the beginning of DS, so I'm unsure of the ICD and whatnot that comes with Foul. If you like this trinket and it has been working well with you, keep it around for a fight you might find needing it more. For me personally, this would not be my trinket of choice. Seal of Seven Signs - Purely a throughput based trinket. I believe the ICD is rather long on the trinket. Tough choice between using this and Windwart Heart, since both are throughput. I suppose it's a matter of personal preference. Windwart Heart - If you don't need the regen, I would use this. Why? It's free healing that I don't need to manage. With mastery procs and haste procs, I would have to manage it more and let it not go to waste. As I said about, it's a personal preference. Would you rather have random hasted/bursted healing? Or random extra healing you don't need to manage?
*jealous Holy/Disc priest that is still running with 2 Heroic FL trinkets and a LFR HoU*
Depending on how your gear is setup, and if you can reforge out of a lot of spirit, a HoU and DMC:T could possibly net you more throughput depending on how you can reforge. I would really have to take a look at your gear to make a solid decision. Almost 1200 spirit with both of those trinkets are nothing to laugh at, especially if you can reforge a crapton of spirit to mast, haste, or even crit at this point. Both give decent bumps of intellect, and to be honest, I recently got SoSS trinket, and I hate it.
As holy, u might not crit as much as the shaman.
So at first i think its good for the shaman so u made a good decision to give him the first WWH u see.
But when it drops again, keep it use it over Foul and switch with Seal on certain fights.
It procs of Sanc Crits, PoH Glyph Crits or any other crit u do with Holy's arsenal of AoE healing spells.
Holy does still crit often enough for this trinket, its ICD is low so it can proc alot.
its still 2% free healing, i got 403 HoU and 397 Seal as Disc (main) and Holy
Its always a waste when u get the haste proc when u dont need it specially when the icd is that long.
Often this is early in a fight, where there's hardly any damage, this haste proc is useless so i smite/hf till 5 sacks (i also run with AA in holy spec (currently Disc/Shadow)). Keeping the buff up for the first AoE damage thats about to happen.
But if u get it on lets say a zon'ozz black phase ur divine Hymn will be massive specially if u have AA.
I skipped on the WWH trinket and gave it to the Shaman for offspec healing cuz he had a 378 trinket and he's now running with Seal and WWH (both 397, and yea his offspec has the same ilvl as me)
Imo Seal and WWH are equal in +HPS because i do get the proc at atleast once while having an AoE phase and the massive haste is like a little personal Hero and if u happen to have AA and DH off CD the HPS increase is even better. If u have an ICD tracker for the Seal u can stretch when it needs to proc if its about to go off CD.
So go with what u find best for ur playstyle, but i won't use Foul over any of the +int trinkets from DS.
The Next WWH will be mine and i prolly use it more than Seal, need to figure out whats best for HM's for my style of play.
Foul Gift is a massively underrated trinket, 40-45% uptime most fights for me, I use it on fights with constant aoe damage where mana isn't an issue.
Seal has far too long an ICD for me to value it. I hate rng as a healer and I hate not knowing when I'll have a haste proc.
I actually bought the VP spirit trinket (Reflection of the Light) recently which I reforged into Haste (already got 25% extra healing from mastery so pushing haste now). Reason I bought this is for Zon'ozz HC and Hagara HC. The /use time lines up perfectly with the Zon'ozz black phases and for every ice/lightning phase on Hagara hc. Handy having an extra SP burst on these phases. Mana isn't an issue for me.
Don't just knock trinkets, find what works best for you on the fights you do. I like reliability as a healer, Foul Gift and Reflection of the Light both have found uses for me in my trinket rotation. HoU obviously is used on all fights with one of the above. On Ppine and Madness, I like pairing Tsunami with HoU so I can push that little more HPS for with the extra regen.
Works for me, find what works for you and be flexible with trinket options.