We use tasks as projects and subtasks as deliverables. So moving a task to another project is a difficult process. You can't just type in the name of the task like you would a project, to move it. You have to move the task to the folder the main tasks exists, select the main task, then drag the other task in as a subtask.
If there were a more intuitive/easier way to move a task into another task as a subtask, would be great.