I love the new diplomatic features of the new expansion, but I hate the Diplomatic Victory option.
First off, the concept of a Diplomatic "Victory" doesn't make sence to me. Just because two empires are currently at peace doesn't mean war can't/won't come later on. Things change, resources become scarce, and westward expansion occurs.
Diplomatic Victory, when turned on, creates a rat race of who can build the most envoys the fastest and build up the most love first. There is no war or conflict, aside from pirates and militia (I've tried playing 4 games with DV on, all against Hard or Unfair AIs). Basically the AI spams Envoys, and to keep from having a "Diplomatic Loss" your forced to do the same.
I do like that when DV is turned on, the AI send envoys, and offer pacts. In short they reciprocate your own generoisity to them (if any). But the rat race of love still overshadows this.
I noticed when DV is turned off, the game is much different. You can send envoys, offer pacts, and "buy" peace for your empire. But the AI (I played 5 games DV off, against Hard/Unfair AI), doesn't reciprocate. The game is not much different than Entrenchment, just more ways to spend your own resources to purchase peace from a war-oriented AI.
What I would like to see is the AI not completely abandon diplomatic efforts on their part when Diplomatic Victory is turned off. Just because diplomacy isn't a path to victory doens't mean it isn't a valuable tool along the way.
Just my two cents.