Just picked up my 4 set and I figured I would share some information I learned about it so far:
- The Golden Apparition is instant. In fact, when you Penance, the Golden Apparition healing will be before any Penance ticks get off.
- With the above statement in mind, Golden Apparition procs are based on when Penance CD is burned. Penance can do 0 healing (immediately interrupting the cast) and a Golden Apparition can still proc. This means it does not proc based on each Penance tick.
- Penance healing or damage can proc the Apparition.
- The Golden Apparition functions with Disc mastery. It can crit and will create a Divine Aegis bubble on its target. I have not tested the 4set with Holy, but I am assuming that it also functions with Holy mastery.
- The healing done by Golden Apparition scales with healing modifiers, including Disc mastery, Archangel, Jin'rokh pools, etc. Its base healing is 100k, and is not effected by intellect or spellpower (based on the tooltip).
I hope this helps! I'm personally always asking questions about new tier bonuses towards the start of tiers, so I figured I'd share some insight, whether or not it's considered pretty obvious. Let me know if there's something you want me to test out. I'll post logs later after doing some raids.