2 up is always faster above 7 to 8 knots. The 2 extra hands available for spi handling and sail trim is the key. Last Dutch Nationals seen again, i was doing singlehanded and i did lost everytime with the spi hoisting and retrieving around 50 meters at least and with 3 rounds it is aprox 150 meters at least ( traing would help but is simple not enough )and when the wind is increasing the singlehander with spi is more in disadvantage.

Hans