So what exactly is the Harvest?

[zenmaster]

IMHO, the key to polarizing sufficiently in a lifetime is reaching a point of acceptance where a fear reaction is not based on the illusory reflection of some aspect of self. Such fear is also manifest as anger.

What's the difference between a "fear reaction" and Ra's "emotional charge?"

emotional charge can be a fear reaction, but it can be any unconscious reaction that stimulates the unconscious (even seemingly positive experience, something that would be the opposite of fear). Fear (as an unconscious reaction) is a way to put more distance between one's awareness and one's self (some unaddressed aspect of self). Hope (as worthy the idealized object of hope may be) is a way to magnify some other aspect of self, which usually has its purpose in not leaving space for something which needs to be addressed. I have found that many people unconsciously feed that charge, because it can offer a sense of certainty and power which they are unable to access otherwise.

Do you feel that fear/anger are the most efficient catalysts to utilize for 3D polarization, with other emotions leading to more nuanced balance after one has sufficiently polarized?

Well as Ra said, everything is catalyst. It starts with the spiritual and works its way down (or up). If it reaches the point of fear/anger then much has already been ignored, and so that would not be very efficient at all. But if people were 100% efficient, there would be no use for the incarnation. After more balance, there is less charge and more of 'you' actually addressing a situation 'for what it is' - that is, at least for how it may be seen from your conscious worldview. The nuance would be a capacity for acceptance and some kind of an appreciation which tends to be more effective in further promoting consciousness.