For me, on paper both Socialism and Capitalism are equally good ideas. Both are capable economic models, that are able to bring much prosperity to the societies in which they are deployed.
The question to which of the both economic model should be applied, should be left to each country to answer. Depending on the culture that each country has, the success that Socialism or Capitalism can achieve is completely different. What's more, in some cases a system that is a hybrid between the two might bring much better results.
All depends on how society works in each country. The values in one might be compatible with Capitalism, while in other they may be more compatible with Socialism.
But, in my mind, the pure form of either of them can't be applied. The main reason for this belief is that in most societies would benefit more from a mixture of both models, in varying degrees. Yes, some lean to one more than the other, but most are more in the center.
At the end, each the self determination of the people of each country should be what determines what economic model to follow.
Specially since what works in one country, doesn't mean it will work in other.
At then end, for me what makes Socialism or Capitalism better, relative to each other, is where are they to be applied. Either one could be the answer to bring prosperity, but it depends on which one is compatible to the core values of each society.