I watched that video a few days ago, I think if he had run the tank on carpet the sound level would have been much lower. Plastic tracks on tiles will always be loud. A tank with plastic gearboxes is very quiet, but the racket from the tracks in the video is what is making most of the noise.
I looked at the site, I maybe wrong but it seems that the gear ratio is the same as a standard HL. I am wondering how a lower ratio might be achieved?
Also it was running with the body off which would also have reduced a lot of the noise if it had been fitted.
It is the price that I am most interested in,
Shaun.