Same deal, unfortunately. The criteria for Notices and my Notifications add-on is the same and works in the same way. As you can have a node within a node within a node etc. then targeting a notice or a notification to a node targets it to its child nodes too.
I've been thinking about extending the criteria in a future version of my add-on (which would by default extend Notices criteria too) so if I do, I'll make "Apply to selected node only" a criteria
Widget Framework is explicitly targeting a specific node ID.
Notices targets a node and its children - as per the wording "pages within node". Something targeted to a category will display the notice in all pages within that node which would be all forums in that category and all sub forums in those forums.
You can't compare the functionality because they're two entirely different things.