In general there is a significant weight savings (100g?) without loss of stiffness when using the BB30 crank because it has an oversize aluminum spindle instead of a smaller diameter steel one. If you have the BB30 bottom bracket, you might as well take advantage of the weight savings. FSA offers BB30 cranks and is very well respected. The SL-K Light model is very good value for the price and comparable in weight to SRAM Red. The K-Force Light is the premium model. Very, very light especially in BB30.