Envoy/Pact System: I'm not partial to having to waste 72-96 supply on a single "ally" to be able to use the pact system. Furthermore, I don't like the pacts... some of them are lame and some of them are OP (I'm lookin' at you, Supply Pact - cuz yer ridiculous), there's no good reason to make certain pacts so ridiculously good. However, because many of them are that good - you're somewhat forced into using them.
Revamped Pirates: Revamped? You're joking right? These things were a mess. Hopefully they will be better after this upcoming patch.
Pirate Missions: Seems kind of redundant, but I suppose if the pirates are ever fixed it might be useful.
Player to Player/AI missions: The missions to the AI are useless, no amount of incentive will make them betray an ally. No dynamism. Unclear on how it affects multi-player.
Relationship System: Also useless... until relationships become interlinked and a relationship w/ one empire affects the relationship and missions w/ another empire - the system is just there to look at. As it stands each relationship exists in a vacuum and that's just plain silly.
Diplomatic Victory: I'm sure some people like it... personally I don't see the point, since diplomacy in this expansion is almost non existent. Not to mention bribery works impossibly well.
Maximum Allied Victory: *shrug*
New AI difficulties: Not really new difficulties... just more cheating. Instead of improving resources, etc, they would have been better served making the AI choose Cap Ships more responsively (AI seems to stock up on Marauders/Akkans/Raptures to a retarded degree), make more intelligent use of special abilities... make use of Super Weapons... and make use of special abilities on Star Bases (I'm lookin' at you, Transcensia). POINT IN CASE: Before making the AI cheat, please make the AI use *all* of the abilities they have at their disposal.
New 'Faster' speed option: I don't use them much, although they are nice to use at the beginning of the game because even with quick start the game feels slow at first. I'm glad they are there for people who like the game to be zippy, though.
Overall: Diplomacy feels like an amateur attempt at a sloppy mod. There are people in the community who produce better work for free. Sorry IC, but you guys really dropped the ball on Diplomacy. Vanilla and Entrenchment were the bomb though. I'm still hoping you guys make a good sequel - or even a decent expansion, but if you're going the expansion route - Diplomacy really needs to be cleaned up before you do.
PS: Thanks for the response template, GoaFan77