it could be true but meaningless. The spot size (with diffraction) only has to be less than about half the atmospheric blur disk to get close to the maximum possible resolution - after that it becomes immaterial how much better it is. In Australian conditions, better than about 1 arc sec is probably good enough in most locations, so anything from a reasonably well made 150mm scope on upwards will be as good as it gets.
Looks like this is a hyperbolic system with a Ross or Rosin 2 element corrector. It will be pretty good, but the extravagant claims really are hyperbole.
http://www.telescope-optics.net/sub_..._corrector.htm is worth a read for the general idea.