I really liked the base game a lot. Tropico 4 had a plethora of options and variety in managing your island.
Modern Times... falls flat. The majority of the new buildings are just "super" versions of previous buildings, to the point that they actually replace them. The Bio Farm replaces the Farm and is just a super farm. The Borehole Mine replaces the Mine and is just a super mine. The Modern Condominium replaces the condominium, Water Treatment Plant replaces Garbage Dump, Organic Ranch replaces Ranch... and so on. Sometimes this even creates problems. The Borehole Mine is physically larger than the mine. I found myself playing a game where the event in which the Borehole Mine had replaced the Mine had already triggered. I couldn't build a mine on a gold deposit I wanted to exploit because the Borehole was too large. A classic mine would have fit just fine. The new content had actually inhibited my ability to play the game!
Some of the new content is cool, like a Car Factory or Electronics Factory. These add some variety to the kinds of economies you can create. The Space Shuttle quest was cute, allowing you to build a deathstar to kill the revbels. However, they come along with a host of other content that's simply rehashed and sometimes even makes the game less playable. The Campaign in the expansion is less interesting than the DLC missions.
Althogether... this expansion is a dissapointment.
Tropico 4 is a good game and some of the DLC for it was pretty clever. This expansion is neither. Avoid.