Are Asteroids Harder to Predict Than Comets?

Comet Schumaker Levy, which hit Jupiter in the 90s, we knew that was going to hit but only a few months in advance because it comes from pretty far out in the solar system where it's hard to track. The more measurements you have of an object, the better you can predict its trajectory. But comets are harder to predict than asteroids and also faster moving. So they're really something to be more worried about than asteroids.