I believe the fine line between love and hate that you are referring to is indifference. I thought XH had this for me and I thought it was worse than hate. Like jaybee mentioned about our meeting, there are some things that came from X that show that he is not indifferent and that is validating in it's own way.
I think that indifference is where you don't give a rip about your X for example because you don't care any more, not even enough to be a PITA to them.
I believe that detachment (in my case anyway) is that you can still love and care for your X but you don't let it "wreck you" and you are in a place of peace and acceptance about "what is" and not what you wish(ed) it to be.
It would be interesting to know what X spouses feel when they are uncomfortable around us but I can only speak for myself. Perhaps they are not detached or perhaps they have guilt or unresolved issues or they still care. Who knows?
