Lots of great responses here. I wanted to chime in with a couple of opinions.

I personally dislike a lot of the rhetoric that goes along with classical (Marxist) communism. The whole concept of the "boss class" and the "worker class" and the "rise of the proletariat" feels to me not like a system, but an "anti-system". This is best explained by comparison.

Aristocracy vs. Capitalism

"Divine right of kings" versus "Capital creates prosperity". No agreement - systems are alien.

Capitalism vs. Communism

"Capital creates prosperity" versus "Capital creates exploitation". Direct opposition - systems are anti.

I do not think that a reactionary system like this will ever work well in practice, as it is based primarily on not being a different system. It is akin to (figuratively, not morally) theological Satanism, which is an anti-system to traditional Christianity. Any anti-system will have trouble existing on its own, as it is designed to react to an existing system. Once the "revolution" comes and a universal comintern government enacted, how will there be a "boss class" or a "proletariat" any longer? The system has nothing to react to; its adherents will lose motivation and began to fight over power, as self-interested and disillusioned humans tend to do.

Another major issue here is patterns of production versus consumption. Entirely human-powered command/planned economies do not work well, as they tend to predict consumption patterns and necessities badly, and often do not provide proper incentives for individuals to produce efficiently. This is a one-two punch of apathy and frustration that will inevitably create gray and black markets... which are a form of capitalism. It is interesting that communist governments in the late 20th century understood this problem, and some were looking into creating super-computers that would be dedicated to nothing more than economic forecasting. Could a communist system work under the aegis of such an instrument? Possibly. I don't know. We would need to experiment. :)

A third issue is the human need for personal relevance that manifests as ambition. In any system, there will be individuals who are more ambitious, more aggressive, more reckless, etc. These people will seek power and seek importance. Others without those qualities may also join power-seeking behavior out of resentment, self-defense, or need to provide an "acceptable" level of social status to their family. These tendencies undermine any attempt at a truly flat organizational structure. Sometimes, this is awful. Human history is rife with abuses of powerful individuals. Sometimes, it is amazing. Human history has also shown that truly visionary or inspiring leaders can lead societies to great feats. But regardless of ideology, realistically, this competition will always occur. This will lead to the creation of a de facto "boss class", even if it is called a politburo, a council, or an inner party. Communism has issues dealing with biologically mandated human behavior, and therefore will have trouble existing unless it can adapt and account for it.