I've noticed no real difference so far since upgrading to 1.2.

Unfortunately, Total War has been a work in progress since Rome so for myself to make things interesting (at least in Vanilla) I've given tons of trait bonuses, extra cash, city and castle upgrades to the AI to make them competitive. I pretty much try and emulate the experience I have facing the Mongols who are the only real competition.

However, my tactics have only helped at least by giving me enemy armies that aren't entirely composed of militia units but they're still not balanced just more powerful units. As someone else said the AI needs to think of its empire as a whole... missile units from one city, heavy infantry from another but that's asking for a whole lot unfortunately.