Oh man, a stat thread. ._.

I'm not sure why people are saying SS is a no-go when some of the linked threads have evidence to the contrary?

Anyway. Here's what I'm thinking of doing: Det/SS. The five points I have left will go into crit or something. Crit is extremely RNG-based, and unless you're stacking it, you're not going to get a significant return out of it. (You should not stack crit as an AST. Some suggest it is useful in Noct, but not nearly the same as a SCH and you will be in Diurnal more often than not. Not to say it's useless though: I use it as secondary melds on my gear since you do get considerable SS from your gear's base stats.) For piety, AST has the best MP management in the game at this point, so this is useless. Accuracy, unless you're melding it and it is required by your raid group, is also pretty iffy. (You will also likely be the main healer alongside a SCH in most serious raid scenarios anyhow.)

Det directly boosts how hard your heals hit. This is the primary stat I stack, both in melds and when looking at base stats. I have somewhere around 780-790 det, and I am able to mostly solo heal many parts of Savage raids while our SCH pushes DPS. I have also out-healed my share if WHMs. SS not only affects cast timers (AST is the fastest healer in the game in Diurnal, so exploit that), but also has some effect on DoT/HoT potency; a huge amount of the healing you do will be dependent on your HoTs.

Ultimately it comes down to personal preference. Det is basically indispensable. If you don't like SS, Crit will give you a higher chance to proc mega heals (crit Essential Dignity ftw). If your raid really requires it (which it SHOULD NOT unless it's a world/server first group), accuracy is the best DPS stat in the game and healers hurt hard for it. Piety is just... kind of a waste no matter how you look at it.