The idea of sub-tasks is to avoid creating multiple tasks for some reasons. I want to make use of it. Sub-task is good way to assign a task to teams and keeping conversation/documentation in one task.
However, whiles task itself can be generated to multiple tasks by assigning to teams, sub-tasks can’t. It is quite inconvenient to create sub-tasks one by one, when you have many team members to assign to.
I think this is something Asana should look into, in addition to better UI for sub-task, like this suggestion.
FYI, I’d love to see the combination of Asana, Workflowy and Myinfo(by milenix.com)