Democracy and Class Struggle finds this explanation of Socialism Utopian and Scientific innovative and useful.
Criticism: Again Markets under Socialism have historically been the basis of a transition back to capitalism ( historical materialist fact in 20th Century) - if you use them we must call them what they are as Lenin did CAPITALISM.
Karl Popper and Marx
Science must be applied to Society: For further understanding of Science and its relationship to Marxism read :
Marxism and Science by J D Bernal