How is it better than the mr clean autodry?

It seems like they are both some kind of filtering system. The mr clean autodry is cheap enough that I can basically just throw it away after a wash and don't have to deal with running and maintaining the CR Spotless.

Or does the autodry not do what it advertises, mainly, change the water so that it won't leave water spots. That's all I am looking for so I can save some time NOT drying the car.