The one that started it all. Symmetrical shape and stance for a balanced center of gravity to increase the ability to weight the deck through turns for better control and energy generation. The sidecuts allow for decreased torsional stiffness between the feet to exploit the board's torsional energy to allow for greater nuances in the turning radius.
The Vanguard was designed and intended for speeds between 0 and 25 mph (0-40km/hr). You can take the board faster with skill and experience, but it is not intended for higher speeds due to its flex characteristics.