Unfortunately, such a system -necessitates- oppression to maintain equality, unless human nature changes to the point that (1) greed stops existing and (2) people will not utilize such a system to become lazy and do nothing. Force will be required to mandate both equality and make sure that people are not taking advantage of the system (e.g. if there is no money, everyone is equal, and I can get everything I want, why work?). While Marx himself did not state that violent revolution was an absolute (Lenin did), Marx did realize that this was possible and likely.
A market economy with reasonable (we can argue about how much) safeguards and regulations has been empirically shown to be the best economic driver.