"But how do we move beyond something as vague as feeling more connected? I'm not terribly satisfied with the existing theories."

"The cognitive version of this is the sense that we are all one being, that we are all connected in some way."

Maybe instead of asking what is this "space" that we are connected to, which seems to be what a lot of people are intending to answer, we should ask why do we visit this "space" after shattering the ego, and why are we connected to it?  What psychological processes could cause this?  As a species, humans are noted as being extremely social creatures.  Maybe that desire to connect with others is a basic psychological concept that emerges when we rid ourselves of all the filters we put onto reality and the ego games.  It seems to me that when I lose my ego, all that is left is just "basic."  Too basic to explain maybe?

I'll come back to this, I'm late for work.  haha.