Now that I've downloaded the picture control I was looking at it in the editor. the AAA one is just the Standard picture control with sharpening set to 7 (instead of default 3). It doesn't put in a custom curve, for example.
The Velvia one is Vivid with sharpening at 5, contrast at 1, brightness at 1, saturation at 2 and hue at 0. The net effect is a contrastier, brighter image.