I liked AOE III, as well, it's just that when it came out I was hoping for AOE II but in 3D, but instead got a game that was a bit different but still good in its own way. 0AD feels like AOE II but in 3D to me.

I just play with friends and sometimes against the AI, so I haven't checked out the multiplayer scene. It looks like there are several build order YouTube videos and threads on Wildfire's forums, though.