In talking to my husband I think I get it a little more. At least I get something. I'm not sure if this is what you are talking about Ceoli, but I get this:
He sees it as quantity vs. quality.
Quantity is a measurement of how many partners/lovers for mono and poly wired people. mono people require only one and poly an undetermined amount, for me three is plenty.
Quality is a description of the nature of the relationships. for mono minded people they believe of themselves that they are able to have one quality relationship and that more would not bring them the quality they require. Poly minded people are able to find quality in the number of people involved in their lives. This is the "fullness" I mentioned before.
That's it, for what it's worth.
(I guess if one doesn't understand the other then books like "ethical slut" would be confusing and threatening for a mono minded person)