I guess it depends on what you are judging communism on. Stability? Growth? Justice? Human rights? All will have different answers.
In my opinion, a communist system is detrimental to human rights due to an unequal balance of power and vested interests from widespread corruption (as stated above).
Let's take the case of China: the government has authority over the citizens and the power within the government rests with a select few. Those in power are not held accountable by the citizens due to a lack of proper election processes, and thus many human rights offenses are committed and there is an overall lack of transparency in government (e.g. Protesters and journalists imprisoned without trial, and I'm sure you can think of heaps more).
However, without communism it's hard to think of where China would be today. It's one of the worlds upcoming superpowers, and has a ridiculously high economic growth rate. It's managed to develop rapidly due to an interesting mix of authoritarian capitalism (Beijing Consensus), which has developed through China's communist roots. With authoritarianism, the government is able to make decisions on development quickly and efficiently (see the One Child Policy, rapid industrialization, etc.) and create a stable way in which to introduce the free market i.e. Capitalism. In other states, such as Bolivia, such a rapid introduction of the free market (as seen through the intervention of the IMF) has had disastrous results, primarily due to a lack of political stability.
So.. Communism is not so great for human rights, but can be great for development. Of course, I've only really used China as an example.
The social justice warrior within me weeps, but the economist inside me is pretty damn interested.