It most certainly is. But I don't consider socialism a "system" or "experiment" any more than I consider capitalism to be either. Human beings will always place value on things differently and be willing to trade effort and/or resources to obtain them (capitalism). And people will always want to collectivize and pool resources and efforts in ways to make more efficient use of resources (socialism). The Soviet system was a monstrosity which talked a good game about socialism but was really just tyranny of the masses by the powerful few, by another name.