K guys,
I was almost exactly the same using the drop-step-push as the crossover and roll. I was a hair faster (.1 or so) using the drop-step-push, but that may be because I work on that style of leaving the most.
So from that I think it boils down to body type and preference. In the drop-step-push method, it takes you a little longer to get going, but get going faster. The length it takes for me to get moving is less than most simply because I was blessed with very fast feet. Someone that has slower feet would probably benefit from the crossover and roll more.
By and large, I will always use both. What determines which method of exiting I use is the stage at hand, the direction of my movement, the distance to the next position, the difficulty of the shot leaving the position, and the terrain.