Hey i got a healing trinket from Maloriak on my holy priest.
It basicly gives me 515 spirit and a on use mana potion(6K).
Should i use this or stick to my blue 346 trinket that gives me int and a spirit proc?
If it depends, what does it depend on? I really dont know much healing theory.
Jar of Ancient Remedies is a huge ton of mana, especially for a Holy Priest who gets the most mileage from Spirit. If you had a 359 Int/Spirit trinket like Core of Ripeness then you could swap those in and out depending on whether you need the extra throughput, but I doubt that losing a massive amount of mana for a 346 that has 285 Intellect and a smaller amount of Spirit would be worth it.
If the only variable in the equation is yourself, then Jar of Ancient Remedies is the better choice.
^ That's what I do. I switch out Jar and Core depending on the fight (and who I'm healing with) and keep the Tol Barad, Mandala, equipped (I like the spirit and the intell proc).