I picked up Age of Empires 3 over the weekend.
+ Graphics are friggin awesome! You can actually see the buildings crumble and such when you fire cannons at them

+Trade Routes and being able to create Native American soldiers is another awesome feature.
+ AI much better than in 2 and can actually do some strategy (for instance, I had build a wall and some outposts to defend my village, they send cavalry to try and attack, it fails, then after a while they come back, but with artillery to be able to break down my defenses).
+ Villagers (settlers in this game) no longer need to go back and forth between the resource they are mining and a depot, they just keep gathering untill the resource is gone. Mills > farms, and there is no more stone to worry about
= The maps are pretty much the same varients they had before, some are better some are worse
- The Field artillery gun is an 'i win' weapon, its supposed to be anti infantry, but if you have a group of about 10 it'll beat the crap out of anything in its path, incluidng buildings and other artillery.
-Defense is harder to do, you can only have 8 outposts in most cases, and only 1 fort (this games version of the castle if anyone ever played 2)
Still a fun game and I know I'll be addicted for a while