First, Some Definitions
OK, first of all, you are mixing words. So I am going to clear that up first, then answer your question. You are saying something like "in capitalistic society ...." and then "in communist society". First of all, you are comparing apples and oranges. Starting at the basics, there is two dimensions to describe modern societies:
- Economic dimension
- Political dimension
The economic dimension has a scale that starts at capitalism and ends at socialism. The political dimension starts at democracy and ends at dictatorship. Of course there are possibilities in between the ends of the scales. So Capitalism is in the economic dimension. Communism, is a mixture of two dimensions, it involves dictatorship (political dimension) and socialism (economic dimension). So you cannot compare it with just capitalism.
Moreover, the original meaning of communism is a utopia, a theory in a book, a myth. What you seem to be referring to is the former Soviet system. That was a socialistic dictatorship. Though, you might know and talk about it as communism, because the US had a propaganda against the Soviet system, where they started to call it communism. But truly, it is not correct to call it that.
Moreover, the real communism, that was described in the book of Marx and Engels, has never been truly used in any society (Stalin had a crazy idea, read the book and misinterpreted it, and said, "I want this now." Scientists tried to explain to him that communism is a utopia. He was stubborn).
Theory of Communism
The original theory of communism involves a huge innovation in manufacturing and robotics etc. Here is just a little bit of the theory so you understand:
It says basically, that in the far far future, we will have such technological advantages, that we will be able to manufacture any product and create any service with almost zero cost. In that society, men will only work for pleasure, in a field that interests them. Every kind of lousy job will be done by robots. And since costs are zero, money has no meaning. People can just wish for anything and it will be theirs. Since there is no money, people are equal financially. And they live in a community. That's where it got the name from.
Back to the Question
But enough of the theory, let's answer your question. I guess you are asking me if socialistic dictatorship can be stable economic strategy. The answer is yes, as long as it has satisfying amount of resources and it does not have to compete with a capitalistic (either democratic or dictatorship) type of society for consumers.
A socialistic dictatorship in that case would be stable, much longer then any kind of capitalistic systems. You see, there are two variations: Capitalistic dictatorship (e.g., People's Republic of China), or capitalistic democracy (e.g., The United States). But the quality of the products and services of this socialistic dictatorship would be very low. So, as soon as it would have to compete for consumers (with low quality), or as soon as it would have to import resources (and pay real prices for them) this system would collapse; that is the real reason for the USSR to have collapsed.
The theoretical communism on the other hand would be a really stable system for a very long time since it would create equilibrium. But it's interesting to note that a really stable system that could be achieved nowadays would be a socialistic democracy. That has never been achieved nor tried ever. That would require the people to agree on dividing all produced goods and services equally among everybody in the society regardless of who created how much actual value.
Unfortunately I am telling you this as I was raised in the Soviet system, then I lived through the systemic change and now I live in the US. I also have a masters in economics (the original name of the university was Marx), comparing modern systems so unfortunately I am telling you this from first hand.
I am going to add one more thing that might be interesting to your question of system stability. to have a stable society, you also need political/legal stability. It is interesting to know that theoretically, you cannot have full democracy and capitalism at the same time. Capitalism will always diminish the poor's right to legal equivalence. Simply, in the US, a rich person can buy better quality of legal help in a civil lawsuit. This is true unfortunately in criminal lawsuits too, though in a limited way. So this basically diminishes some parts of democracy. Theoretically, a socialistic democracy would be much better for the masses (who would be poor and have only limited democracy in a capitalistic democracy), so a socialistic democracy would be the real form of democracy. Unfortunately, that will not likely happen, since everybody, rich and poor would have to agree on the equal allocation of wealth and legal rights.
Edit: Additional thoughts
Continuing this thought, I would like to emphasize the importance of political/legal stability in any system. Doubtless, the Soviet system was physically threatening, and intimidating, every second of the day—I lived in it with constant fear so I know. That was a brutal, primitive system, that really mostly physically intimidated you. But it was stable, since people were scared. Uprisings were impossible, and basic democratic right were diminished. The political "elite" were physically terrorizing the masses. But they provided a minimal secured financial living. Now I live in the US, a capitalistic democracy, and I see that it is a much more sophisticated system. But it has an "elite," the top 1%, who is financially abusing the masses. And it creates separation of the wealthy into certain zip codes, the rotting away of poorer communities, with ever higher crime rates, etc. That also creates political instability. So I believe that for long stability, you need some level of financial equilibrium too. A capitalistic democracy very much lacks such equilibrium.
So, to your question, the final answer is that a socialistic democracy would be the most stable.