This widget is great for me, the only problem I have is that "groups who can see this", behaves differently to the way it does on advertisements (native invision)
If I have a member who is in group A and group B, and I decide to hide show adverts to everyone except group B, they are hidden from that member.
However, if I do the same for TXT & PHP Widget, the member will still be able to see the widget, because he is in Group A.
Logically your way makes the most sense compared to the description of the field, but it's less useful in my experience.