When using av widget that sorts tasks by date all tasks that are subtasks will be collapsed under, and sorted as per the start/due date of the main/parent task. This might be OK in some cases, but in my experience most often not.
For me one of the main reasons of using subtasks is to split the work that needs to be done into logical bulks either by required personell/resources og due to some sort of a time dependency. The latter is the case that I want to focus on here.
Given the example that subtask A should be started or finished on dates that are different than subtask B, then most likely the timespan for the parent task would probably be set as the sum of these two tasks, given that these are all the tasks in the set. Further then it makes no sense that subtask A and B should be collapsed and sorted based on the date configuration of the parent task. These are, related yes, but individually defined tasks that should be sorted by their own configuration. Actually there is never any correct date configuration for the parent task in this situation.
Granted, this case is simple enough to keep an eye out for, but multiply this with more parent tasks with several subtasks, and it gets worse to handle.
Seems this is also the situation with other sorting options like Status as well, just the Date thing was how the issue arose in my case.
How about allowing for an option on "exploding" aggregated task sets in the widget configuration menu? Showing both the parent, subtask A and subtask B as per their own configuration. Side by side if so were.
EDIT: You have done exactly this in the "My to-do" view under Personal spaces! There I can choose the Task list display as "Hierarchical" or "Plain", this is exactly what I need in my widgets. So please make this a feature option for task widgets! :)