i would like to second the playing of Radius Rome 2 mod.... its fantastic. started a new game and wow you can notice the difference, so much to mention but here are the highlights.
enemy now builds stronger army's (no more 15 groups of slingers), food/squalor is 100x easier to manage, higher army/navy cap, units don't rout in the fist 10 seconds of battle (now they fight until most of the group is dead), better diplomacy (different thresholds for friendly/hostile)
and that's just to list off-hand, many more and would recommend you follow the link and read up on them. they can be used as one complete mod or you can use one of them broken down in smaller parts. easy to install, just copy one file to data directory (no overwrite of files and easy to uninstall)
was about ready to give up on the game, its such a worthless pile of beta ****. don't know how CA think it was OK to release as is, and don't give me that SEGA crap. CA was responsible, and also lied to everyone by showing alpha game-play (battle of Carthage) that's thousand times better that the final version