I love 0 A.D.! The only issue I have ran into is it slows down so much that it is basically unplayable with more than 4 players or so (or a few AI players). I've been meaning to jump in for awhile and help improve things.
I don't know what it's like now, but when I used to work on it we badly needed a new short-range pathfinder design. That and the range manager would pretty much just die once there was a significant number of units.
Yay, so catapults and ships don't get stuck on each other anymore? Yay, I might have to get back into it (except I have a 'real job' and side projects etc now...).
Is the multiplayer turn length still really long? (500ms IIRC)