My conclusion is that the Soviet system is actually superior.
I think North America has had the advantage at times in having slightly more superstar talents, probably always a significant edge in goaltending and some flukeish wins in international competition have made people think differently.
1. Lovable Bobby Clarke breaking Kharlamov's leg in a shockingly close Summit Series.
2. The Flyers, as two-time defending Cup champs, crushing the CRA team and saving face for the NHL, which was otherwise utterly dominated.
3. Miracle on Ice
4. The 1987 Canada Cup, which was decided by the fact that Canada had probably its two greatest stars, Gretzky and Lemieux, at the peak of their physical skills.
5. Scott Stevens' nuclear hit on Kozlov in the 1995 SCF that led to a 4-0 sweep, which was seen as a vindication of the NHL rough style over a skilled soft Russian player.
There's no doubt that a lot of these series featured physical play as a huge equalizer (<3 Ed Van Impe), but the Soviets had something like a 26-8 record vs. NHL teams in exhibitions. Of course those teams were stacked from the star, but they were generally playing the NHL's best teams.