NOTE: At the moment, Tropico 3 is on special on Steam, US$10 for the main game and US$6.70 for the expansion. If you're on the fence, they are both worth it for the price.
Tropico 3 is one of those games that is utterly infuriating because it's so close to being fantastic, but because of one tiny design decision it loses a lot of its sparkle.
In this case it's the difficulty curve, due mostly to the staticness of happiness - the start of a map can be really hard, because everyone is demanding a basic level of services that cost a lot of construction time, specialists and money that you don't have, and most buildings take a year or two to start turning a profit, so then you get rebellions, coups and invasions all over the place.
But then once you get past this, you're suddenly swimming in more money than you can possibly spend, and once the people have a basic level of contentment (church, pub+restaurant, clinic) they really don't get much more demanding and you can win every election with 95% support (even without rigging!) for 30 years and never worry about rebels while everyone still lives in cardboard shacks. Sort of survive 5 years then easy victory.
It took me a while to realise this, but Absolute Power actually takes some fairly significant measures to combat this. Firstly, the factions are a LOT more demanding, with major and minor demands, and the demands increase significantly over time. Suddenly you can see the happiness actually decreasing, and I've found that elections are a LOT closer - I've needed to suspend elections with well over 50% happiness. It's now vital to pander to at least a couple of major voting blocs. There's actually a point to bribing/assassinating faction leaders now, and also to faction shaping - it can be well worth it to take measures to boost/eliminate certain factions, and there are a lot more options for doing so. The new loyalist faction is fun too, and lets you work towards an actively brainwashed society. Overall, all the fun tyrannical things that were completely unnecessary in the original are now much more relevant, and there's a whole load more tyrannical edicts too.
On the flip side, the new edict to shoot Juanito (the radio announcer) gives you a 3-year grace period against the rebels, which makes the frustrating early game much easier (and makes rebel yell a great "hard mode").
Unfortunately, the same can't be said for the major powers, which remain disappointingly impotent. Makes the super-cool nuclear project a bit useless except for scenario goals, which is a shame.
The new buildings are a mixed bag. The wind turbine is the best of the lot - a cheap option that provides a bit of electricity (based on height) for a couple of buildings without the need for a massive outlay, heaps of space, or hordes of college graduates. Not as good value as a regular powerplant, but not such massive overkill in the early game.
The garbage dump is also great, and the smaller garage size is a godsend.
The marina looks great, but doesn't add much gameplay-wise. The radar dish is more a scenario thing, but also cheap and kind of useful. The grade school is more for a long-term megalomania approach - ban contraception, close the borders and brainwash the kiddies into the nationalist and loyalist factions, while making them better workers. I'm just not sure it provides quite enough benefit.
The statues are pretty cool - massively expensive and a good way to convert wads of cash into popularity, as well as shape the factions. Plus a rotating golden statue of yourself is just way too cool.
And the new "rebel announcer" woman is kinda cool for making the radio less repetitive (and shooting the other guy scares her off too). And she's got some good lines (I quite like the one about conformist wind turbines that won't rotate against the wind)
And the new scenarios are mostly quite a lot of fun. The jewel is undoubtedly the one where your island is stuck in a timewarp, and you start with almost no buildings, and have to "research" new technologies civ-style like mining, writing, embezzlement etc. Very clever civ parody that is both very funny and plays really well.
The missile-building and financial crisis ones are also excellent, and really only the "serial killer" one doesn't work.
Anyway, for me it made Tropico 3 a LOT more fun, even if it didn't really add terribly much. Maybe not worth the full asking price, but definitely worth it at $7 on steam.