i've read somewhere that the crit on-use trinket from shadopan is pretty good for resto.
Its not bad but the spirit gives more straight up mana regeneration. If mana isn't an issue anymore than i say go for it. Other wise i would recomend staying with the DMC trinket and Scroll of Revered Ancestors until you can get the healing trinket out of Terrace which has the highest spirit regen of the tier as well as some nice intellect.
right now I am using the vial of icharous blood and the relic of chi gi. I want will of the emperor, but it hasn't dropped for me yet. I prefer proc trinkets instead of on use. On use is good, but is just another button I have to press and time right.