How was the demo ? Installed it but no time to play it until like 3-4pm...
EDIT: I tried it, this game doesn't seem too bad. It's actually fun to manage everything, even though i prefer games like Civ 5 much more, since diplomacy, social policies and your own behavior towards trading/territory spread/armed forces will directly influence your gameplay in a way or another...
Tropico 4 offers more advanced management, but it will never suit players expecting gameplay that is focused on foreign relations.
Definitely worths the 30 bucks if you love this type of game though, the game is polished at maxed graphics and the mecanics are still fairly easy to understand for total noobs.