it is far better to stick with the well-worn convention that a "Reply" button in a web forum interface meaning "make my reply to the group"
p.s. And the reason it's better is because it's the order in which we think. It's not better because it's a well-worn convention. The convention IS the well-worn convention because it matches how we think. As you said, Brian, Y!G and Groups.io are currently the outliers. -- J