Now first off I want to clarify that I don't play a priest, but I'm asking this question on behalf of someone that plays one. Not knowing the class extremely well I thought this might be a decent place to get an answer from people more knowledgeable about priests than myself.
Anyway, the guy wanted to know whether the spell Atonement proc'd the trinket Eye of Blazing Power. Apparently he did a BH and it only proc'd 4 times during it, and he was wondering whether he should use that trinket versus using a Rune of Zeth.
Both Atonement and the PW Shield glyph proc this trinket
Keep in mind it has a 45 second ICD, so it will proc 50+ seconds or so as Disc. Holy can get it to proc much closer to the ICD b/c EoL can trigger the proc.
The boss in BH doesn't take long, 4 procs sounds about right. That's ~60k healing extra, over the course of about 4 minutes it works out to be ~250 HPS
Honestly, I'm not a fan of this trinket and I've passed on it each time it dropped. Even if this heals were twice as powerful, there's very little control over where it goes. You could end up increasing your overheal or healing a blood worm. I much prefer my Tsunami Deck and Alchemy flask atm. The trinkets Dragon Soul are sexy =)