Destroy object on collision or check position

In the scenario where multiple `rigidBody`s moving due to `addForce` goes out of view (say, top of view) and is no longer needed then what technique should be prefered? 1. Destroying the `gameObject` by detecting collision - by creating a `collider` object and destroying the `rigidBody` when it collides with it 2. Destroying the `gameObject` by first checking it's `rigidBody` position in `Update` or `FixedUpdate` Premature optimization or not, I'd still like to know Thanks,