I think the "internet rep" for x39 is simply based on the fact that up until recently, most people were shooting the ammo out of surplus rifles, and those barrels weren't really built for accuracy. So the reputation the cartridge has, is deeply engrained in the type of rifle it was shot out of. Throw it in a bolt gun like the Ruger, with a good barrel, and you will have better groups (As the video shows)
Now.... What I would like to see is, how this $700 CAD rifle stacks up against the pricier CZ offering, AND the cheaper (if you can find one) Norinco Bushranger 7.62X39 (man I miss those being available!)
EDIT: forgot to note, great video! Thanks for the review!