No indication of opened window(s) on other workspaces
While changing the behavior:
One problem was created when application from the same group is opened on working and other workspace(s) on the same time.
User selects Quit in Quicklist and it closes all running instances of application across all workspaces and there is no indication some open instances from this group of application exist on other workspaces because user can't just simply summon them all on current workspace like it could before. The only way to find out if other opened instances of the same application exist on other workspaces too is to switch among all available workplaces before using Quit from Quicklist!