Ok, it's all about thresholds.
In MA2, if the max FPS that can be generated is 100fps and you set the limit to 58fps with Vsync ON, it's easy to get 25% CPU usage or so.
Since GA does so much more calculation, the max FPS that can be generated on my system seems to be 40fps. CPU usage ramps up dramatically to generate those last few FPS.
So since the "Limit to FPS" slider is a bit off-kilter (setting it to 36 yields 32, setting it to 40 yields 36), I set my "Limit to FPS" slider to 40 and I turned off Vsync with the Ctrl-V key.
Without affecting the animation, I get about 36-38fps and 22% CPU usage.
Frankly, I would like to see a future version of MA2/MAT/FONA/GA that does a brief test on initial run to see how many max FPS it can generate and then instead of a "Limit FPS" slider (this would be moved to an Advanced panel), just have a "Limit CPU usage to only what is necessary for smooth animation" checkbox.
In this case, my FPS would automatically limit itself to 38fps or 40fps and my CPU usage would be a perfect 22%.