Awesome gameplay, but still has problems with Vista
The updated graphics do require a lot more horsepower, I could run SC maxed out with perfect frame rates. I can run FA maxed out as well, but the frame rate is noticeably less-than-perfect. I currently have a GeForce 8800 GTS 640 MB, running at 1680 x 1050 with all settings at max and anti-aliasing at 16x.
The AI is greatly improved. In SC, I usually just sat in my base and minded my own business for an hour or so while I build up, and then I'd send an army and smash the enemy. Now, even on easy, I'm getting swarmed by squadrons of attack bombers within the first fifteen minutes. My priorities have definitely had to shift to keep up, we turtles now have to immediately start on defense, and I mean immediately. Build two mass extractors, a few power generators, and a factory, and then immediately put your commander on anti-air defenses.
The Aeon have a new experimental unit, a building, which actually keeps your mass and energy income positive, no matter how much you're using. It's awesome multiplayer since you can be the Aeon and build these experimentals and give them to allies. Once you have one, you no longer need to worry about power generators and mass extractors/fabricators, however you have to guard it well. If it's destroyed, it has the same blast as a nuclear weapon.
The game also introduces "engineering stations," essentially a building that functions as an engineer. It will automatically repair any friendly units or buildings and try to reclaim enemy units that are within its radius of effect. You can build these throughout your turret defensive lines and they'll try to keep your turrets at full HP.
I would rate the game a 10, but it still crashes for me!!!