Hey I know what you mean. No Galciv does not have the excellent diplomacy that SMAC/SMACX had. That game is all alone with how it was designed.
The diplomacy has not improved that much but all the other aspects of the game have. I was sort of bored with the first release of Galciv after the initial newness of the game wear off. Altarian Prophecy brought new life into the game. Especially with all the new Modding abilities, new techs, more events, extra races etc. I promise you that it will not disappoint you. I feel SMAC/SMACX was thee best 4x strategy game ever made.
I strongly suggest using some of the excellent mods made for the game. I am bias to a degree but I find Icho_Tolot mods to be the best around. Using his Mod packs will change the entire game.
Moser_The_Alchemists also has some great Mods. Not to discount anyone else's wonderful Mods, these are just my personal favorites.
NeoTech Gaming http://neotechgaming.com A sci-fi themed website featuring Galactic Civilizations.