I can't provide a very detailed, overall view as of yet, but in my current campaign as Russia I've noticed the AI forming and using firing lines. They also melee less, especially when it is more oportunistic to exchange vollys. I had one interesting battle, a small battle, there was no way I could win but I was pleased with the AI performance. I set up some infantry to fire on his approaching melee troops, got off one volly and they engaged, I had two units to his one in the melee but was losing. Meanwhile, he moved two units of calvary to a flanking position and hesitated until my units were ready to rout and finished the job. I must say, I'm not the best at this game but I though the AI didn't perform too badly.