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.
Does it have much of a multiplayer scene? Are there any sites to look at good build orders. I might have to try it again.