picks are snags. A bow, by nature, stays above the strings and can doesn't inherently impede speed.

Yes, speed is important. Good, clean sound it even better. The best players can do both at the same time. When I listen to David Grier, the man is playing so cleanly -- with so much clarity between notes -- that I often think he's not playing that fast....until I pick up my guitar or mandolin and try to play along.