Well, it will hopfully work this time (load glitch), if it works, that alone is worth the purchase. From what Ive seen they've not only added new buildings, but lots of edicts and new mechanics, with the return of some old features. Im still trying to determine if that first person camera mode is a new mechanic, or just somthing in the trailer. I just like the gameplay, SimCity meets a strategy RPG.
I've seen tropico 3 in stores a few times, but the box was never enough to push me into a buy, but if Xarnac is making a thread about the new game in the series, it must be worth a try.
If you like SimCity and easy, fun micro managing (doing things to your populous), and simply building and being creative with the architecture and scenery (Making giant parks, mazes, attractions and gardens with the tools and "beautification" scenery. Everything from statues of yourself, to War Memorials, to exotic trees). Then Id actually say dont rent 3, but rent 4 and see if its good. Like others have said, 3 is like 4, but with more additions and will hopfully work right this time.
The Demo to 3 is on live, download it and check it out. If you have a 360 that is.