I've done several tanks now with the stuff--and will always choose to rinse. Not necessarily crystal clear rinsing, but at least knocking the dust back a significant amount.
My first time using it, I didn't rinse, was super careful filling and wondered why there was such a fuss about it. Right up until I did a major re-scape that involved pulling up major root systems. Took massive water changes, filter cleanings and close to a week to get the water clear again.