Firstly, we love Carcassonne, it is really a fantastic game and if you haven't bought the main game yet, do so you will not be disappointed. We also have various expansions to the game such as Inns and Cathedrals, Builders & Traders and Towers.
The other expansions complement the main basis of the game perfectly and are therefore highly recommended. However, Towers, for me, is different in that the tactics that must be employed become quite significantly altered (as are well described elsewhere in other reviews), to such an extent that it severely upsets the game. We have played the game with this expansion several times with the hope and belief that over time, as we become more used to it, our tactics will develop, but to be frank we have now decided to abandon using this expansion, other than the extra tiles and the cardboard tower that come with the set and revert to the basic game plus the other expansion sets.