I've seen the demo in person and it's good. But why do you find it so hard to believe I'm not going accept one person's opinion when so many others hold the opposite view. And frankly I'd dare say physics is on the side of being co-planer as well.
For example, isn't drive power delivered more efficiently when pulleys are aligned in the same plane??
Besides, proof is in the pudding---and my saw was greatly improved in ease of adjusting blade tracking with even the minor change a couple of bushings made.