The Hammer Strength unilateral supinated-grip pulldown is one of my favorite machines. It's nearly impossible to duplicate with free weights what this machine can do.
Several training methods work great on this machine, like maximum tension alternating pulls (hold one side isometrically in the contracted position at the bottom while the other side is moving). It also works great with bands for added accommodating resistance.
The strength and conditioning field is like no other. Coaches have bitter enemies and die-hard devotees – and sometimes a person will qualify as both depending on the day of the week. There are insane egos and there are humble, incredibly bright coaches who go unnoticed. Finally, there are a lot of coaches who people really don't get.