My questions was more towards relevance of the old parsys component in newer versions of AEM. With introduction of layout container, do you still see a use for the old parsys? Or layout container should be used as the container component in 100% of the cases?
With AEM 6.4 - you should be using editable templates and each editable template has a layout container. In the layout container - you can add policies that define which components are allowed to be used in the layout container.