When working in Grid mode, every created object gets aligned to the activated Grid. Except for Groups, when Groups get created in Grid mode, they get aligned to World Coordinate System. Like this, the created Group's Local Coordinate System has no meaning relative to the objects which it contains.
Using Local Coordinate System is useful in some cases, it would be nice if creating Groups this way, their Local Coordinate System would be aligned with the Working Grid.
Only way I could achieve this is to create the objects in World Coordinate System, Group them, and then align the created group to the Working Grid, but this is not very efficient. Or I always have to activate the needed Working Grid, and move the group around in Reference Coordinate System, if I want to imitate the Group's own cordinate system.
It would be useful and logical for Groups to have this feature!