I admit I'm quite new to the game but after playing several rounds, I am convinced that The Returning Armada (RA) and Phase stabilizer capabilities set this race far and above the others, especially on large maps.  I've seen posts on the RA so this seems to be something on people's minds.

For balance issues, I would be for changing/removing the RA, and allowing the other races the vast conveniece of phase stabilizer structures as well.  However I'm not sure how this would work as far as balancing, perhaps the vasari would have to be given some other end-game thing.