I have a choice for my Augments...

12 END and 18 Willpower

or

12 END and 18 Power

For Sage DPS and Sage Healer...which is best? Maybe a mixture....any comments?

If I already have Crit over 30% (over 35% with the Smuggler buff), is it still better to go with the Willpower Augments?

From what I've read elsewhere, once Crit goes above 30% you get diminishing returns for it. Or is the Crit Chance from the Willpower stat different?

From what I've read elsewhere, once Crit goes above 30% you get diminishing returns for it. Or is the Crit Chance from the Willpower stat different?

Diminishing returns applies only to the specific rating, not the percentage value. Willpower and Crit Rating both apply their relevant increases to your final critical hit chance using separate DR curves. The DR curve on Willpower is so shallow that you're pretty much *never* going to hit the softcap (iirc, someone calculated it and it's somewhere in the 10k region).

Diminishing returns applies only to the specific rating, not the percentage value. Willpower and Crit Rating both apply their relevant increases to your final critical hit chance using separate DR curves. The DR curve on Willpower is so shallow that you're pretty much *never* going to hit the softcap (iirc, someone calculated it and it's somewhere in the 10k region).

This. I don't know why people continue to recycle this fallacy that crit chance has a soft cap. Crit RATING has a diminishing returns curve that becomes prohibitive in the 300 range. But your main stat improves your crit chance way past 30 percent. With the DPS specs, you want your crit chance to be close to 35 percent un-buffed at the campaign gearing level, which is possible because you are going to have Willpower well over 2,000 to add to crit rating somewhere in the 300 range.

My sage (healing spec) had close to 2500 Willpower a couple weeks ago (buffed) and I started tweaking my augments to see if really willpower was giving me the bang for my buck that I wanted. As I started procuring the DG gear, I noticed the mods and such were very high in willpower compared to power.

All I have seen over time are the calculations from people showing "stack willpower, it gives you the best bang for your buck" but as I started tweaking, I noticed this isn't the case; at least for my healing results. I have swapped out my high willpwr/low pwr mods with lower willpower/higher pwr mods - and my stats are now buffed around 2200 willpower and ~1100 pwr if I remember right.

my incredibly foolproof scientific method of checking out my salvation procs shows i've increased my standard proc by about 20hp/tick and my crit ticks by about 20-30 hp/tick. My crit ticks were higher, but I also played around with my surge rating and alacrity some, so that accounted for some of the dip in my high end crit numbers.

Right now my salvation heals me (yes, I know it is different for everyone because of additional spec'd buffs) for 511 normal ticks and 900 crit ticks. when I started this process my normal ticks were around 485 and my crits were in the 870's.

again, i'm not claiming to know it all - but I've noticed that power is giving me a bit more bang for my buck over willpower as i've fine tuned things.

This is because the mods you are talking about do not give you a 1:1 trade for willpower and power, which is why you want to stay away from lettered mods. On a purely 1:1 basis, willpower gives you more bang for your buck than power. But lettered mods give you more willpower at the sacrifice of more than 1 secondary stat, almost 2:1 in most cases.

For example, Advanced Aptitude Mod 27 gives you 56 willpower and 44 power. Advanced Aptitude Mod 27A gives you 72 willpower and 13 power. So if you take the lettered mod over the regular one, you gain 16 willpower for 31 power. If it were itemized so you could trade 31 power for 31 willpower, you would want to take the willpower. But 16 willpower for 31 power isn't a good trade. Two points of power are worth more than one point of willpower.