I played the EUIV demo for about 10-20 hours in November. I had tried Hearts of Iron 3 before, but as much as I desperately wanted to like that game, it was SO DRY that I had to quit. Watching the battles be fought (...boxes "fighting") felt like watching my calculator crunch numbers then asking me to believe that those numbers were "my soldiers." Just not enough meat on the bone.
That in mind, I was much more open to EUIV due to it looking more like a game and less like crinkled newspaper. I am very much intrigued by the idea of "intelligent diplomacy" which honestly no game has ever given me. I was VERY close to buying it but didn't, I just don't know if it can draw me in as much as Civ can. Very tempted by the idea of realism though. If the diplomacy is well-done, if playing peacefully is at least as effective as just taking everything you want, and if the game makes you feel like an 18th century monarch, then I'm in.